or role=\"main\" tags found. Semantic HTML reduces code bloat and allows both assistive technology and web crawlers to parse content more efficiently.",
"wsid": "3.ensure code follows good semantic practices",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#ensure-code-follows-good-semantic-practices",
"assessor": "script",
"example": "\n \n Page Title
\n Content goes here.
\n \n",
"pageCount": 2,
"pages": {},
"criteria": null
},
{
"guideline": "17.1",
"title": "Missing print style sheet",
"urgency": "low",
"detail": "Add a @media print stylesheet to ensure the page is optimized for paper-saving printing.",
"wsid": "17.printed documents",
"assessor": "script",
"example": "@media print {\n /* Hide non-critical navigation and backgrounds */\n nav, .ads, header, footer { display: none; }\n body { font-size: 12pt; color: #000; background: #fff; }\n a::after { content: \" (\" attr(href) \") \"; } /* Show URLs */\n}",
"pageCount": 1,
"pages": {},
"criteria": {
"title": "Printed documents",
"description": "Design your process to reduce the need for paper documents. Where the production of paper documents is essential, it should be designed to have the lowest impact possible. Include a CSS print style sheet and test it with different types of content. Encourage saving documents in digital formats over paper-based storage and archiving.",
"resources": [
{
"A Guide To The State Of Print Stylesheets In 2018": "https://www.smashingmagazine.com/2018/05/print-stylesheets-in-2018/",
"Changing Paper Consumption": "http://www.greenschools.net/article.php-id=75.html",
"CSS Design: Going to Print": "https://alistapart.com/article/goingtoprint/",
"GR491 - 6-3044 - Paper Printing": "https://gr491.isit-europe.org/en/crit.php?id=6-3044-uxui-the-flows-of-dematerialization-are-sometimes-broken",
"GR491 - 9-5076 - Ink Saving": "https://gr491.isit-europe.org/en/crit.php?id=9-5076-frontend-the-flows-of-dematerialization-are-sometimes-broken",
"GreenIT - 0031 - Provide a print CSS": "https://rweb.greenit.fr/en/fiches/RWEB_0031-provide-a-css-print",
"How to Become an Eco Web Designer": "https://onextrapixel.com/how-to-become-an-eco-web-designer/",
"OpQuast - 190 - The website offers styles dedicated to printing.": "https://checklists.opquast.com/en/digital-quality/the-site-provides-at-least-one-style-sheet-for-printing",
"OpQuast - 191 - The content of each page can be printed without printing the navigation blocks.": "https://checklists.opquast.com/en/digital-quality/the-content-of-each-page-can-be-printed-without-navigation-blocks",
"Printed - Print Friendly CSS Library": "https://printedcss.com/",
"UI Tools": "https://designsustainably.eu/uitools/",
"United Nations SDGS - Goal 11 - Human Habitats": "https://sdgs.un.org/goals/goal11#targets_and_indicators",
"United Nations SDGS - Goal 12 - Consumption & Production": "https://sdgs.un.org/goals/goal12#targets_and_indicators",
"Using UX Design to Build a Sustainable Future": "https://uxmag.com/articles/using-ux-design-to-build-a-sustainable-future",
"Which Fonts Use The Least Ink & Toner?": "https://www.tonerbuzz.com/blog/which-fonts-use-the-least-ink-toner/"
}
],
"guideline": {
"categoryId": "2",
"categoryName": "User Experience Design",
"id": "17",
"title": "Reduce the impact of downloadable and physical documents",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-the-impact-of-downloadable-and-physical-documents",
"subheading": "Reduce the need for physical documents as much as possible by allowing the saving of well-labeled, optimized digital downloads. Include a print style sheet to avoid resource waste."
},
"benefits": [
{
"Accessibility": "Providing a range of inclusively designed downloadable documents in a variety of formats benefits those with accessibility needs as they can choose the ideal format for their device and use case.",
"Environment": "Reducing the need to print documents or providing a print friendly style sheet reduces emissions associated with paper, ink, and the act of printing.",
"Performance": "Compressing or otherwise optimizing documents means they can be downloaded faster, avoiding users needing to wait to view documents prepared for offline viewing."
}
],
"example": null
}
}
]
},
"siteGuidance": {
"siteCount": 2,
"singleSiteScan": false,
"sites": [
{
"origin": "https://www.w3.org",
"pageCount": 98,
"sharedRecommendations": [
{
"area": "expected-files",
"urgency": "medium",
"title": "Add sitemap.xml at site origin",
"detail": "sitemap.xml is missing for all sampled pages on https://www.w3.org."
},
{
"area": "expected-files",
"urgency": "low",
"title": "Publish .well-known/security.txt",
"detail": ".well-known/security.txt is missing for all sampled pages on https://www.w3.org."
},
{
"area": "offline-support",
"urgency": "high",
"title": "Introduce service worker support",
"detail": "No sampled pages on https://www.w3.org indicate service worker support for offline resilience."
},
{
"area": "offline-support",
"urgency": "high",
"title": "Support offline fallback behavior",
"detail": "Offline page behavior was not detected across sampled pages on https://www.w3.org."
},
{
"area": "optimization",
"urgency": "medium",
"title": "Fix recurring optimization bloat at shared layer",
"detail": "Minify JavaScript recurs across 94 pages on https://www.w3.org (est. 595.87 KB aggregate savings)."
},
{
"area": "compression",
"urgency": "medium",
"title": "Prioritize recurring compression fixes",
"detail": "Minify JavaScript before transfer recurs across 94 pages on https://www.w3.org (est. 595.87 KB aggregate savings)."
},
{
"area": "offline-support",
"urgency": "high",
"title": "Prioritize recurring offline/caching improvements",
"detail": "Add service worker support is needed across 98 pages on https://www.w3.org."
}
],
"recurringCompression": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "medium",
"pageCount": 94,
"totalEstimatedSavingsBytes": 610171
},
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"pageCount": 49,
"totalEstimatedSavingsBytes": 887352
},
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "high",
"pageCount": 23,
"totalEstimatedSavingsBytes": 5704484.2
},
{
"id": "uses-optimized-images",
"title": "Improve image encoding quality/size",
"urgency": "medium",
"pageCount": 5,
"totalEstimatedSavingsBytes": 435617
}
],
"recurringOptimization": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"pageCount": 94,
"totalEstimatedSavingsBytes": 610171,
"totalEstimatedBlockingMs": 0
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"pageCount": 55,
"totalEstimatedSavingsBytes": 0,
"totalEstimatedBlockingMs": 55818
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"pageCount": 50,
"totalEstimatedSavingsBytes": 1816638,
"totalEstimatedBlockingMs": 0
},
{
"id": "unminified-css",
"title": "Minify CSS",
"pageCount": 49,
"totalEstimatedSavingsBytes": 887352,
"totalEstimatedBlockingMs": 0
},
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"pageCount": 23,
"totalEstimatedSavingsBytes": 5704484.2,
"totalEstimatedBlockingMs": 0
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"pageCount": 23,
"totalEstimatedSavingsBytes": 4021683,
"totalEstimatedBlockingMs": 0
},
{
"id": "uses-optimized-images",
"title": "Compress oversized image assets",
"pageCount": 5,
"totalEstimatedSavingsBytes": 435617,
"totalEstimatedBlockingMs": 0
}
],
"recurringOfflineOpportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"pageCount": 98
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"pageCount": 98
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"pageCount": 98
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"pageCount": 98
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"pageCount": 98
}
],
"recurringDependencies": [],
"recurringRuntimeSignals": [],
"pageSpecific": [
{
"url": "https://www.w3.org/WAI/fundamentals/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 72,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 50,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 438.01 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 438.01 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 413.13 KB."
},
{
"title": "Remove unused CSS",
"urgency": "low",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 15.19 KB."
}
]
},
{
"url": "https://www.w3.org/careers/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 92,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "medium",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 184.10 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "medium",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 143.98 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/developers/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 80,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 654.83 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 654.83 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 393.77 KB."
}
]
},
{
"url": "https://www.w3.org/developers/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 78,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 654.83 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 654.83 KB."
}
]
},
{
"url": "https://www.w3.org/about/leadership/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 78,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 253.85 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "medium",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 143.98 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
{
"url": "https://www.w3.org/ecosystems/e-commerce/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 78,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 23,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 524.83 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 524.83 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 282.05 KB."
}
]
},
{
"url": "https://www.w3.org/ecosystems/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 66,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 675.24 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 675.24 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/ecosystems/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 63,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 730.00 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 730.00 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 541.46 KB."
}
]
},
{
"url": "https://www.w3.org/2024/09/TPAC/w3c-30.html",
"securityScore": 29,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 15,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 50,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 359.38 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "medium",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 60.78 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 7.71 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 2.09 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/about/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 45,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 24,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "medium",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 144.37 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "medium",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 144.37 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "medium",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 91.24 KB."
}
]
},
{
"url": "https://www.w3.org/about/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 44,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 24,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "medium",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 144.37 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "medium",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 144.37 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 47,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 272.28 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "low",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 38.33 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
{
"url": "https://www.w3.org/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 46,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 259.15 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "low",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 38.33 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
{
"url": "https://www.w3.org/events/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 41,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1193 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 33.83 KB."
}
]
},
{
"url": "https://www.w3.org/guide/",
"securityScore": 29,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1185 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.35 KB."
}
]
},
{
"url": "https://www.w3.org/help/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 25,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 38.56 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1214 ms."
}
]
},
{
"url": "https://www.w3.org/policies/code-of-conduct/",
"securityScore": 29,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 8,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 5.15 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 5.15 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "low",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 101 ms."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
}
]
},
{
"url": "https://www.w3.org/ja/help/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 23,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 38.56 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 38.56 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "low",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 29.96 KB."
}
]
},
{
"url": "https://www.w3.org/news-events/w3c-tpac/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 20,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 21.46 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1212 ms."
}
]
},
{
"url": "https://www.w3.org/support-us/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1043 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.58 KB."
}
]
},
{
"url": "https://www.w3.org/news/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1191 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 33.81 KB."
}
]
},
{
"url": "https://www.w3.org/blog/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1042 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 33.67 KB."
}
]
},
{
"url": "https://www.w3.org/press-releases/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1206 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.56 KB."
}
]
},
{
"url": "https://www.w3.org/policies/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1189 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.76 KB."
}
]
},
{
"url": "https://www.w3.org/news/2026/first-public-working-drafts-for-the-linked-web-storage-lws-1-0-authentication-suite/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1202 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.05 KB."
}
]
},
{
"url": "https://www.w3.org/news/2026/five-first-public-working-drafts-published-by-the-verifiable-credentials-working-group/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1198 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.18 KB."
}
]
},
{
"url": "https://www.w3.org/news/2026/first-public-working-draft-css-image-animation-module-level-1/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1186 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.75 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/news-events/w3c-tpac/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 21.46 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 21.46 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "low",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 10.59 KB."
}
]
},
{
"url": "https://www.w3.org/news-events/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 15,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1215 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.85 KB."
}
]
},
{
"url": "https://www.w3.org/about/corporation/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 15,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1215 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.59 KB."
}
]
},
{
"url": "https://www.w3.org/contact/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1182 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.63 KB."
}
]
},
{
"url": "https://www.w3.org/get-involved/promote/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 13,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1189 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.98 KB."
}
]
},
{
"url": "https://www.w3.org/groups/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1202 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.79 KB."
}
]
},
{
"url": "https://www.w3.org/resources/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 12,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1207 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.82 KB."
}
]
},
{
"url": "https://www.w3.org/reports/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1208 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.20 KB."
}
]
},
{
"url": "https://www.w3.org/evangelists/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1216 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.78 KB."
}
]
},
{
"url": "https://www.w3.org/help/search/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 16,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1201 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.22 KB."
}
]
},
{
"url": "https://www.w3.org/ja/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 15,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 15.29 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1152 ms."
}
]
},
{
"url": "https://www.w3.org/staff/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 11,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1112 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 68.65 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/events/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 35,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/email/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1177 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.90 KB."
}
]
},
{
"url": "https://www.w3.org/about/positive-work-environment/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1157 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.92 KB."
}
]
},
{
"url": "https://www.w3.org/copyright/document-license/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1217 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.00 KB."
}
]
},
{
"url": "https://www.w3.org/standards/review/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 409 ms."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
}
]
},
{
"url": "https://www.w3.org/liaisons/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 13,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1153 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.92 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/standards/review/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ja/support-us/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/support-us/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 33,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ecosystems/media/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 17,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 22.38 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 22.38 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "low",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 22.26 KB."
}
]
},
{
"url": "https://www.w3.org/membership/list/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 17,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "medium",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 40.94 KB."
},
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 8.74 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1309 ms."
},
{
"title": "Remove unused JavaScript",
"urgency": "medium",
"detail": "Reduce dead JS and split bundles to avoid shipping non-critical code. Estimated byte savings: 50.09 KB."
}
]
},
{
"url": "https://www.w3.org/TR/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 10,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 68.46 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 756 ms."
}
]
},
{
"url": "https://www.w3.org/ja/news/2026/w3c-invites-implementations-of-geolocation/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ja/news/2026/group-note-use-of-large-language-models-in-standards-work/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ja/news/2026/updated-w3c-recommendation-geolocation/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ja/policies/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ja/about/corporation/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/news/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/blog/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/press-releases/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/get-involved/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/International/i18n-drafts/nav/about",
"securityScore": 29,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 0,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 2.27 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 564 ms."
},
{
"title": "Right-size images for viewport",
"urgency": "low",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 15.56 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 2.27 KB."
}
]
},
{
"url": "https://www.w3.org/blog/2026/2026-breakouts-day-recap/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 15,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1224 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.50 KB."
}
]
},
{
"url": "https://www.w3.org/ja/contact/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/get-involved/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/news-events/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/standards/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 4,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.31 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 321 ms."
}
]
},
{
"url": "https://www.w3.org/developers/tools/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 14,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1201 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.87 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/get-involved/promote/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 4,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/resources/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 4,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/standards/about/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 589 ms."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
}
]
},
{
"url": "https://www.w3.org/groups/other/tag/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 2067 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.38 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
{
"url": "https://www.w3.org/about/press-media/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.22 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 304 ms."
}
]
},
{
"url": "https://www.w3.org/mission/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.21 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 463 ms."
}
]
},
{
"url": "https://www.w3.org/ja/help/search/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/standards/about/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/groups/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/reports/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 6,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/standards/types/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 558 ms."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
}
]
},
{
"url": "https://www.w3.org/invited-experts/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/standards/types/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/liaisons/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/email/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/about/positive-work-environment/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/invited-experts/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/membership/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 24,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 38.99 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "medium",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 49.11 KB."
}
]
},
{
"url": "https://www.w3.org/about/diversity/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.34 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 300 ms."
}
]
},
{
"url": "https://www.w3.org/mission/accessibility/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.17 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 300 ms."
}
]
},
{
"url": "https://www.w3.org/mission/internationalization/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.75 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 463 ms."
}
]
},
{
"url": "https://www.w3.org/mission/privacy/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.46 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 306 ms."
}
]
},
{
"url": "https://www.w3.org/mission/security/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 2,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.76 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 300 ms."
}
]
},
{
"url": "https://www.w3.org/zh-hans/membership/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 4,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 24,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 38.99 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "medium",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 49.11 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 38.99 KB."
}
]
},
{
"url": "https://www.w3.org/zh-hans/developers/tools/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 5,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/ecosystems/publishing/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 3,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 31.11 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 8.15 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "low",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 38.18 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 31.11 KB."
}
]
},
{
"url": "https://www.w3.org/ja/blog/2026/past-present-and-future-an-update-on-w3cs-strategic-objectives-on-the-37th-anniversary-of-the-web-proposal/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 3,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 20,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "medium",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 45.75 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
}
]
},
{
"url": "https://www.w3.org/zh-hans/standards/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 1,
"optimizationScore": 84,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/about/press-media/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 1,
"optimizationScore": 44,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/zh-hans/mission/",
"securityScore": 14,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 1,
"optimizationScore": 42,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 30,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
},
{
"url": "https://www.w3.org/translations/",
"securityScore": 29,
"dependencyScore": 0,
"expectedFilesScore": 45,
"compressionScore": 0,
"optimizationScore": 0,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 50,
"urgency": "high",
"topRecommendations": [
{
"title": "No major compression opportunity detected",
"urgency": "low",
"detail": "Compression signals look healthy in current Lighthouse audits; continue enforcing compression and asset encoding in CI/CD."
},
{
"title": "No obvious optimization bloat signals",
"urgency": "low",
"detail": "No major easy-win optimization opportunities were detected from current Lighthouse signals."
},
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
}
]
}
]
},
{
"origin": "https://auth.w3.org",
"pageCount": 2,
"sharedRecommendations": [
{
"area": "expected-files",
"urgency": "medium",
"title": "Add sitemap.xml at site origin",
"detail": "sitemap.xml is missing for all sampled pages on https://auth.w3.org."
},
{
"area": "expected-files",
"urgency": "low",
"title": "Publish .well-known/security.txt",
"detail": ".well-known/security.txt is missing for all sampled pages on https://auth.w3.org."
},
{
"area": "security-headers",
"urgency": "medium",
"title": "Enable Strict-Transport-Security site-wide",
"detail": "HSTS is missing across all sampled HTTPS pages on https://auth.w3.org."
},
{
"area": "offline-support",
"urgency": "high",
"title": "Introduce service worker support",
"detail": "No sampled pages on https://auth.w3.org indicate service worker support for offline resilience."
},
{
"area": "offline-support",
"urgency": "high",
"title": "Support offline fallback behavior",
"detail": "Offline page behavior was not detected across sampled pages on https://auth.w3.org."
},
{
"area": "optimization",
"urgency": "medium",
"title": "Fix recurring optimization bloat at shared layer",
"detail": "Remove unused CSS recurs across 2 pages on https://auth.w3.org (est. 70.58 KB aggregate savings)."
},
{
"area": "compression",
"urgency": "low",
"title": "Prioritize recurring compression fixes",
"detail": "Minify CSS before transfer recurs across 2 pages on https://auth.w3.org (est. 37.02 KB aggregate savings)."
},
{
"area": "offline-support",
"urgency": "high",
"title": "Prioritize recurring offline/caching improvements",
"detail": "Add service worker support is needed across 2 pages on https://auth.w3.org."
}
],
"recurringCompression": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"pageCount": 2,
"totalEstimatedSavingsBytes": 37907
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"pageCount": 2,
"totalEstimatedSavingsBytes": 12259
}
],
"recurringOptimization": [
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"pageCount": 2,
"totalEstimatedSavingsBytes": 72273,
"totalEstimatedBlockingMs": 0
},
{
"id": "unused-javascript",
"title": "Remove unused JavaScript",
"pageCount": 2,
"totalEstimatedSavingsBytes": 48478,
"totalEstimatedBlockingMs": 0
},
{
"id": "unminified-css",
"title": "Minify CSS",
"pageCount": 2,
"totalEstimatedSavingsBytes": 37907,
"totalEstimatedBlockingMs": 0
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"pageCount": 2,
"totalEstimatedSavingsBytes": 12259,
"totalEstimatedBlockingMs": 0
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"pageCount": 2,
"totalEstimatedSavingsBytes": 0,
"totalEstimatedBlockingMs": 2133
}
],
"recurringOfflineOpportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"pageCount": 2
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"pageCount": 2
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"pageCount": 2
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"pageCount": 2
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"pageCount": 2
}
],
"recurringDependencies": [],
"recurringRuntimeSignals": [],
"pageSpecific": [
{
"url": "https://www.w3.org/Member/",
"securityScore": 33,
"dependencyScore": 4,
"expectedFilesScore": 50,
"compressionScore": 13,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1075 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.29 KB."
}
]
},
{
"url": "https://www.w3.org/users/myprofile/",
"securityScore": 33,
"dependencyScore": 4,
"expectedFilesScore": 50,
"compressionScore": 13,
"optimizationScore": 100,
"offlineScore": 100,
"languageScore": 0,
"mediaHintsScore": 26,
"urgency": "high",
"topRecommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1058 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.29 KB."
}
]
}
]
}
]
},
"crossPagePatterns": {
"heavyAssetPatterns": [
{
"key": "script|www.youtube.com|/s",
"label": "script assets from www.youtube.com/s",
"resourceType": "script",
"domain": "www.youtube.com",
"pageCount": 14,
"totalTransferBytes": 5546403,
"exampleUrl": "https://www.youtube.com/s/_/ytembeds/_/js/k=ytembeds.base.en_US.Jn-9HPgVKSU.2021.O/am=AAAABA/d=1/exm=base,root/ed=1/br=1/rs=AGKMywFIPd8H83JB8R7S3Dnm-hTNowb--w/m=r78Drb"
},
{
"key": "stylesheet|www.youtube.com|/s",
"label": "stylesheet assets from www.youtube.com/s",
"resourceType": "stylesheet",
"domain": "www.youtube.com",
"pageCount": 14,
"totalTransferBytes": 774736,
"exampleUrl": "https://www.youtube.com/s/_/ytembeds/_/ss/k=ytembeds.base.oRmnRxCtskc.L.W.O/am=AAAABA/d=0/br=1/rs=AGKMywHkqPKx19LNLTFOD88ZyDOWYDGFJw"
},
{
"key": "script|www.youtube-nocookie.com|/s",
"label": "script assets from www.youtube-nocookie.com/s",
"resourceType": "script",
"domain": "www.youtube-nocookie.com",
"pageCount": 12,
"totalTransferBytes": 5360432,
"exampleUrl": "https://www.youtube-nocookie.com/s/player/8456c9de/player_embed_es6.vflset/en_US/base.js"
},
{
"key": "stylesheet|www.youtube-nocookie.com|/s",
"label": "stylesheet assets from www.youtube-nocookie.com/s",
"resourceType": "stylesheet",
"domain": "www.youtube-nocookie.com",
"pageCount": 12,
"totalTransferBytes": 710260,
"exampleUrl": "https://www.youtube-nocookie.com/s/player/8456c9de/www-player.css"
},
{
"key": "image|www.w3.org|/cms-uploads",
"label": "image assets from www.w3.org/cms-uploads",
"resourceType": "image",
"domain": "www.w3.org",
"pageCount": 7,
"totalTransferBytes": 3109038,
"exampleUrl": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/w30c-pattern.jpeg"
},
{
"key": "image|www.w3.org|/comm",
"label": "image assets from www.w3.org/comm",
"resourceType": "image",
"domain": "www.w3.org",
"pageCount": 4,
"totalTransferBytes": 1977852,
"exampleUrl": "https://www.w3.org/comm/assets/graphics/w3cx-accessibility-intro-twitter-only.png"
},
{
"key": "script|f.vimeocdn.com|/p",
"label": "script assets from f.vimeocdn.com/p",
"resourceType": "script",
"domain": "f.vimeocdn.com",
"pageCount": 2,
"totalTransferBytes": 624085,
"exampleUrl": "https://f.vimeocdn.com/p/4.46.43/js/player.module.js"
}
],
"recurringTargets": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"pageCount": 57,
"totalEstimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later."
},
{
"title": "Modularize heavy script asset from www.youtube.com",
"urgency": "high",
"pageCount": 14,
"totalEstimatedSavingsBytes": 3159233,
"strategy": "Load this script only on pages or interactions that require it; prefer dynamic import and feature-level bundles."
},
{
"title": "Modularize heavy image asset from www.w3.org",
"urgency": "high",
"pageCount": 13,
"totalEstimatedSavingsBytes": 5027206,
"strategy": "Serve a smaller placeholder first and load this asset only when the user scrolls to or requests the component."
},
{
"title": "Modularize heavy script asset from www.youtube-nocookie.com",
"urgency": "high",
"pageCount": 12,
"totalEstimatedSavingsBytes": 5360432,
"strategy": "Load this script only on pages or interactions that require it; prefer dynamic import and feature-level bundles."
},
{
"title": "Modularize heavy script asset from f.vimeocdn.com",
"urgency": "medium",
"pageCount": 2,
"totalEstimatedSavingsBytes": 432933,
"strategy": "Load this script only on pages or interactions that require it; prefer dynamic import and feature-level bundles."
},
{
"title": "Modularize heavy font asset from www.w3.org",
"urgency": "medium",
"pageCount": 2,
"totalEstimatedSavingsBytes": 376361,
"strategy": "Subset or defer this font so full font payloads are only fetched when needed."
}
],
"recurringOrigins": [
{
"domain": "www.w3.org",
"pageCount": 16,
"totalTransferBytes": 7148939
},
{
"domain": "www.youtube.com",
"pageCount": 14,
"totalTransferBytes": 6321139
},
{
"domain": "www.youtube-nocookie.com",
"pageCount": 12,
"totalTransferBytes": 6070692
},
{
"domain": "f.vimeocdn.com",
"pageCount": 2,
"totalTransferBytes": 624085
}
],
"designSystemGuidance": [
"This same heavy image pattern appears on 13 pages. Fix it once in the shared template, CMS block, or design system component to reduce load across the whole site.",
"These 3 script bundles are recurring modularization targets. Move the fix to the shared bundle or component boundary so every affected page gets lighter at once.",
"These 3 modularization targets recur across multiple pages. Centralize the fix at the component or bundle level instead of treating each page separately.",
"Heavy assets from www.w3.org recur across 16 pages. Review whether that dependency should be deferred, optimized, or loaded conditionally."
]
},
"results": [
{
"url": "https://www.w3.org/",
"status": "ok",
"finalUrl": "https://www.w3.org/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 719585,
"co2Grams": 0.275659629219,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "The World Wide Web Consortium (W3C) develops standards and guidelines to help everyone build a web based on the principles of accessibility, internationalization, privacy and security.",
"robots": "",
"canonical": "",
"ogTitle": "W3C",
"ogDescription": "The World Wide Web Consortium (W3C) develops standards and guidelines to help everyone build a web based on the principles of accessibility, internationalization, privacy and security.",
"ogType": "website",
"ogUrl": "https://www.w3.org/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 20,
"tabletSmallTapTargets": 21,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 4,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 20,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 21,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 20 small targets on mobile and 21 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "58440",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed4058d06c956-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:11:00 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f09413d5edb46c7",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,newsArticles,pressReleases,members"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 20,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 8,
"imagesWithLazy": 5,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 14,
"lazyImages": 11,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 11/14 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "![\"Description\"](\"image.webp\")
\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 46,
"urgency": "medium",
"totalEstimatedSavingsBytes": 329707.75,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "high",
"estimatedSavingsBytes": 265366.75,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
},
{
"id": "uses-optimized-images",
"title": "Improve image encoding quality/size",
"urgency": "low",
"estimatedSavingsBytes": 39254,
"detail": "Re-encode oversized images and tune compression quality for significant byte savings."
},
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18958,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 259.15 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "low",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 38.33 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 570193.75,
"totalEstimatedBlockingMs": 998,
"opportunities": [
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 265366.75,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 259 KiB",
"urgency": "high",
"sourceAuditId": "modern-image-formats"
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 205146,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 200 KiB",
"urgency": "high",
"sourceAuditId": "uses-responsive-images"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35340,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 998,
"displayValue": "Est savings of 1,000 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "uses-optimized-images",
"title": "Compress oversized image assets",
"detail": "Re-encode large images to reduce transfer weight without visible quality loss.",
"estimatedSavingsBytes": 39254,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 38 KiB",
"urgency": "low",
"sourceAuditId": "uses-optimized-images"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18958,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 259.15 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 200.34 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.51 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 998 ms."
},
{
"title": "Compress oversized image assets",
"urgency": "low",
"detail": "Re-encode large images to reduce transfer weight without visible quality loss. Estimated byte savings: 38.33 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 699617.75
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 683.22 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 683.22 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 2,
"urgency": "low",
"transferBytes": 719585,
"css": {
"unusedBytes": 35340,
"ratio": 0.049111640737369455,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35340,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 11,
"urgency": "medium",
"transferBytes": 719585,
"estimatedDeferrableBytes": 35340,
"renderBlockingMs": 998,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35340
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35340,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 998,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "medium",
"estimatedSavingsBytes": 174707,
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/w30c-pattern.jpeg",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 10,
"urgency": "low",
"transferBytes": 719585,
"estimatedRedundantBytes": 35340,
"redundancyRatio": 0.049111640737369455,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35340,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35340,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 18,
"urgency": "medium",
"totalTransferBytes": 719585,
"heavyRequestCount": 2,
"heavyBytes": 285415,
"heavyRatio": 0.39663834015439453,
"heavyRequests": [
{
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/w30c-pattern.jpeg",
"transferSize": 174707,
"resourceType": "image",
"mimeType": "image/jpeg",
"domain": "www.w3.org"
},
{
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/ryan-quintal-US9Tc9pKNBU-unsplash.jpg",
"transferSize": 110708,
"resourceType": "image",
"mimeType": "image/jpeg",
"domain": "www.w3.org"
}
],
"groupedByType": [
{
"resourceType": "image",
"count": 2,
"transferBytes": 285415
}
],
"groupedByOrigin": [
{
"domain": "www.w3.org",
"count": 2,
"transferBytes": 285415
}
],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
{
"title": "Modularize heavy image asset from www.w3.org",
"urgency": "medium",
"estimatedSavingsBytes": 174707,
"strategy": "Serve a smaller placeholder first and load this asset only when the user scrolls to or requests the component.",
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/w30c-pattern.jpeg",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,000 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,000 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "modern-image-formats",
"title": "Serve images in next-gen formats",
"description": "Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).",
"score": 0.5,
"displayValue": "Est savings of 259 KiB",
"impact": "medium",
"wsg": {
"categoryId": "2",
"categoryName": "User Experience Design",
"id": "11",
"title": "Optimize media to reduce resource use",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use",
"subheading": "Ensure all media - including audio, video, animation, images, and other novel formats, when deemed necessary in the design, are optimized, correctly sized and formatted, use lazy loading where appropriate, with a usage policy in place."
},
"assessor": "script",
"issueTemplate": "## Improve Serve images in next-gen formats\n\n- Lighthouse audit: modern-image-formats\n- Current value: Est savings of 259 KiB\n- WSG guideline: 11 Optimize media to reduce resource use\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use\n\n### Why this matters\nImage formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "uses-optimized-images",
"title": "Efficiently encode images",
"description": "Optimized images load faster and consume less cellular data. [Learn how to efficiently encode images](https://developer.chrome.com/docs/lighthouse/performance/uses-optimized-images/).",
"score": 0.5,
"displayValue": "Est savings of 38 KiB",
"impact": "medium",
"wsg": {
"categoryId": "2",
"categoryName": "User Experience Design",
"id": "11",
"title": "Optimize media to reduce resource use",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use",
"subheading": "Ensure all media - including audio, video, animation, images, and other novel formats, when deemed necessary in the design, are optimized, correctly sized and formatted, use lazy loading where appropriate, with a usage policy in place."
},
"assessor": "script",
"issueTemplate": "## Improve Efficiently encode images\n\n- Lighthouse audit: uses-optimized-images\n- Current value: Est savings of 38 KiB\n- WSG guideline: 11 Optimize media to reduce resource use\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use\n\n### Why this matters\nOptimized images load faster and consume less cellular data. [Learn how to efficiently encode images](https://developer.chrome.com/docs/lighthouse/performance/uses-optimized-images/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/ja/",
"status": "ok",
"finalUrl": "https://www.w3.org/ja/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 268057,
"co2Grams": 0.10268765083980001,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "W3C",
"lang": "ja",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Homepage",
"robots": "",
"canonical": "",
"ogTitle": "W3C",
"ogDescription": "Homepage",
"ogType": "website",
"ogUrl": "https://www.w3.org/ja/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 14,
"tabletSmallTapTargets": 14,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 4,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 14,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 14,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 14 small targets on mobile and 14 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "58345",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed43b9950c956-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:11:08 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f0943c62f46835d",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,newsArticles,pressReleases,members"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 11,
"lazyImages": 8,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 8/11 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 15,
"urgency": "low",
"totalEstimatedSavingsBytes": 40739.55,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "low",
"estimatedSavingsBytes": 15657.55,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 15.29 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 81257.55,
"totalEstimatedBlockingMs": 1152,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1152,
"displayValue": "Est savings of 1,150 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35692,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 15657.55,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 15 KiB",
"urgency": "low",
"sourceAuditId": "modern-image-formats"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 4826,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 5 KiB",
"urgency": "low",
"sourceAuditId": "uses-responsive-images"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1152 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.86 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 15.29 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "low",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 4.71 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 257267.91666666666
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 251.24 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 251.24 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 5,
"urgency": "low",
"transferBytes": 268057,
"css": {
"unusedBytes": 35692,
"ratio": 0.13315078509421505,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35692,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 14,
"urgency": "high",
"transferBytes": 268057,
"estimatedDeferrableBytes": 35692,
"renderBlockingMs": 1152,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35692
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35692,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1152,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 15,
"urgency": "low",
"transferBytes": 268057,
"estimatedRedundantBytes": 35692,
"redundancyRatio": 0.13315078509421505,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35692,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35692,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 268057,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,150 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,150 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "modern-image-formats",
"title": "Serve images in next-gen formats",
"description": "Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).",
"score": 0.5,
"displayValue": "Est savings of 15 KiB",
"impact": "medium",
"wsg": {
"categoryId": "2",
"categoryName": "User Experience Design",
"id": "11",
"title": "Optimize media to reduce resource use",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use",
"subheading": "Ensure all media - including audio, video, animation, images, and other novel formats, when deemed necessary in the design, are optimized, correctly sized and formatted, use lazy loading where appropriate, with a usage policy in place."
},
"assessor": "script",
"issueTemplate": "## Improve Serve images in next-gen formats\n\n- Lighthouse audit: modern-image-formats\n- Current value: Est savings of 15 KiB\n- WSG guideline: 11 Optimize media to reduce resource use\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use\n\n### Why this matters\nImage formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/zh-hans/",
"status": "ok",
"finalUrl": "https://www.w3.org/zh-hans/",
"performanceScore": 0.93,
"bestPracticesScore": 1,
"transferBytes": 735404,
"co2Grams": 0.28171959388560003,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "W3C",
"lang": "zh-hans",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "万维网联盟（World Wide Web Consortium简称W3C）制定标准和指南，基于无障碍、国际化、隐私及安全的原则构建一个服务于所有人的web。",
"robots": "",
"canonical": "",
"ogTitle": "W3C",
"ogDescription": "万维网联盟（World Wide Web Consortium简称W3C）制定标准和指南，基于无障碍、国际化、隐私及安全的原则构建一个服务于所有人的web。",
"ogType": "website",
"ogUrl": "https://www.w3.org/zh-hans/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 27,
"tabletSmallTapTargets": 29,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 4,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 27,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 29,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 27 small targets on mobile and 29 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "58396",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed475bdf2c956-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:11:18 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f0942bdca41835d",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,newsArticles,pressReleases,members"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 20,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 8,
"imagesWithLazy": 5,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 14,
"lazyImages": 11,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 11/14 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 47,
"urgency": "medium",
"totalEstimatedSavingsBytes": 343152.9,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "high",
"estimatedSavingsBytes": 278815.9,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
},
{
"id": "uses-optimized-images",
"title": "Improve image encoding quality/size",
"urgency": "low",
"estimatedSavingsBytes": 39254,
"detail": "Re-encode oversized images and tune compression quality for significant byte savings."
},
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 272.28 KB."
},
{
"title": "Improve image encoding quality/size",
"urgency": "low",
"detail": "Re-encode oversized images and tune compression quality for significant byte savings. Estimated savings: 38.33 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 583752.9,
"totalEstimatedBlockingMs": 1014,
"opportunities": [
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 278815.9,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 272 KiB",
"urgency": "high",
"sourceAuditId": "modern-image-formats"
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 205267,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 200 KiB",
"urgency": "high",
"sourceAuditId": "uses-responsive-images"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1014,
"displayValue": "Est savings of 1,010 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35333,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "uses-optimized-images",
"title": "Compress oversized image assets",
"detail": "Re-encode large images to reduce transfer weight without visible quality loss.",
"estimatedSavingsBytes": 39254,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 38 KiB",
"urgency": "low",
"sourceAuditId": "uses-optimized-images"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 272.28 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 200.46 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1014 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.50 KB."
},
{
"title": "Compress oversized image assets",
"urgency": "low",
"detail": "Re-encode large images to reduce transfer weight without visible quality loss. Estimated byte savings: 38.33 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 714597.9333333332
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 697.85 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 697.85 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 2,
"urgency": "low",
"transferBytes": 735404,
"css": {
"unusedBytes": 35333,
"ratio": 0.04804570005058444,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35333,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 11,
"urgency": "high",
"transferBytes": 735404,
"estimatedDeferrableBytes": 35333,
"renderBlockingMs": 1014,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35333
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35333,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
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"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "medium",
"estimatedSavingsBytes": 174678,
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/w30c-pattern.jpeg",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
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"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
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}
}
],
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"categoryName": "Web Development",
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"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
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}
},
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}
]
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],
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"title": "Remove unnecessary or redundant information",
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"title": "Remove unnecessary or redundant information",
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"categoryName": "Web Development",
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"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
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"title": "Modularize bandwidth-heavy components",
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"wsg": {
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"categoryName": "Web Development",
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"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
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"score": 0,
"displayValue": "Est savings of 1,010 ms",
"impact": "high",
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},
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"impact": "medium",
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},
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},
{
"auditId": "modern-image-formats",
"title": "Serve images in next-gen formats",
"description": "Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).",
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"displayValue": "Est savings of 272 KiB",
"impact": "medium",
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},
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"issueTemplate": "## Improve Serve images in next-gen formats\n\n- Lighthouse audit: modern-image-formats\n- Current value: Est savings of 272 KiB\n- WSG guideline: 11 Optimize media to reduce resource use\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use\n\n### Why this matters\nImage formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
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"title": "Efficiently encode images",
"description": "Optimized images load faster and consume less cellular data. [Learn how to efficiently encode images](https://developer.chrome.com/docs/lighthouse/performance/uses-optimized-images/).",
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"categoryId": "2",
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"title": "Optimize media to reduce resource use",
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"subheading": "Ensure all media - including audio, video, animation, images, and other novel formats, when deemed necessary in the design, are optimized, correctly sized and formatted, use lazy loading where appropriate, with a usage policy in place."
},
"assessor": "script",
"issueTemplate": "## Improve Efficiently encode images\n\n- Lighthouse audit: uses-optimized-images\n- Current value: Est savings of 38 KiB\n- WSG guideline: 11 Optimize media to reduce resource use\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use\n\n### Why this matters\nOptimized images load faster and consume less cellular data. [Learn how to efficiently encode images](https://developer.chrome.com/docs/lighthouse/performance/uses-optimized-images/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
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"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 30,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 6,
"imagesWithLazy": 2,
"imagesWithoutLazy": 4
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "4 of 6 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 6,
"lazyImages": 2,
"totalIframes": 1,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/6 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 4,
"urgency": "low",
"totalEstimatedSavingsBytes": 25082,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60216,
"totalEstimatedBlockingMs": 321,
"opportunities": [
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35134,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 34 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 321,
"displayValue": "Est savings of 320 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.31 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 321 ms."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 278551.4593109869
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 272.02 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 272.02 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 2,
"urgency": "low",
"transferBytes": 637646,
"css": {
"unusedBytes": 35134,
"ratio": 0.05509953798816271,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35134,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 4,
"urgency": "medium",
"transferBytes": 637646,
"estimatedDeferrableBytes": 35134,
"renderBlockingMs": 321,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35134
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35134,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 321,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy script from f.vimeocdn.com",
"area": "script",
"urgency": "high",
"estimatedSavingsBytes": 216352,
"url": "https://f.vimeocdn.com/p/4.46.43/js/player.module.js",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "medium",
"estimatedSavingsBytes": 91573,
"url": "https://www.w3.org/cms-uploads/globe.svg",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 59,
"urgency": "medium",
"providerCount": 2,
"requestCount": 5,
"transferBytes": 339708,
"notGreenCount": 1,
"unknownCount": 0,
"scripts": [
{
"hostname": "f.vimeocdn.com",
"resourceType": "script",
"requestCount": 2,
"transferBytes": 312038,
"sampleUrl": "https://f.vimeocdn.com/p/4.46.43/js/player.module.js",
"greenCheck": {
"hostname": "f.vimeocdn.com",
"checked": true,
"status": "not-green",
"green": false,
"hostedBy": null,
"hostedByWebsite": null,
"listedProvider": null,
"partner": null,
"modified": "2026-04-23T12:14:55.122102",
"supportingDocuments": [],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/f.vimeocdn.com",
"error": null
}
},
{
"hostname": "www.gstatic.com",
"resourceType": "script",
"requestCount": 3,
"transferBytes": 27670,
"sampleUrl": "https://www.gstatic.com/cv/js/sender/v1/cast_sender.js?loadCastFramework=1",
"greenCheck": {
"hostname": "www.gstatic.com",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Google Cloud",
"hostedByWebsite": "https://cloud.google.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-25T09:52:50",
"supportingDocuments": [
{
"id": 108,
"title": "Sustainability at Google",
"link": "https://sustainability.google"
},
{
"id": 1364,
"title": "Google 2024 Environmental Report",
"link": "https://www.gstatic.com/gumdrop/sustainability/google-2024-environmental-report.pdf"
},
{
"id": 1365,
"title": "Alphabet 2024 CDP Climate Change Response",
"link": "https://www.gstatic.com/gumdrop/sustainability/alphabet-2024-cdp-climate-change-response.pdf"
},
{
"id": 1366,
"title": "Google 2024 Supplier Responsibility Report.",
"link": "https://www.gstatic.com/gumdrop/sustainability/google-2024-supplier-responsibility-report.pdf"
},
{
"id": 1367,
"title": "Alphabet FY2023 Environmental Indicators Assurance Letter",
"link": "https://www.gstatic.com/gumdrop/sustainability/alphabet-fy2023-environmental-indicators-assurance-letter.pdf"
},
{
"id": 1368,
"title": "3Degrees Cloud Services Review Statement",
"link": "https://services.google.com/fh/files/misc/3degrees_cloud_services_review_statement_final.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.gstatic.com",
"error": null
}
}
],
"recommendations": [
{
"title": "Maintain a third-party JavaScript inventory",
"urgency": "medium",
"detail": "Track 2 third-party script origin(s) and assign an owner plus business justification for each."
},
{
"title": "Reduce third-party script payload and requests",
"urgency": "high",
"detail": "Defer non-critical tags, remove unused vendors, and gate scripts behind consent or user interaction."
},
{
"title": "Prioritize greener alternatives for third-party providers",
"urgency": "high",
"detail": "1 third-party script origin(s) are not confirmed green in the Green Web Foundation dataset."
}
]
},
"redundancy": {
"score": 11,
"urgency": "low",
"transferBytes": 637646,
"estimatedRedundantBytes": 35134,
"redundancyRatio": 0.05509953798816271,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35134,
"displayValue": "Est savings of 34 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35134,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 22,
"urgency": "medium",
"totalTransferBytes": 637646,
"heavyRequestCount": 2,
"heavyBytes": 312038,
"heavyRatio": 0.48935929967411385,
"heavyRequests": [
{
"url": "https://f.vimeocdn.com/p/4.46.43/js/player.module.js",
"transferSize": 216352,
"resourceType": "script",
"mimeType": "application/javascript",
"domain": "f.vimeocdn.com"
},
{
"url": "https://f.vimeocdn.com/p/4.46.43/js/vendor.module.js",
"transferSize": 95686,
"resourceType": "script",
"mimeType": "application/javascript",
"domain": "f.vimeocdn.com"
}
],
"groupedByType": [
{
"resourceType": "script",
"count": 2,
"transferBytes": 312038
}
],
"groupedByOrigin": [
{
"domain": "f.vimeocdn.com",
"count": 2,
"transferBytes": 312038
}
],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
{
"title": "Modularize heavy script asset from f.vimeocdn.com",
"urgency": "medium",
"estimatedSavingsBytes": 216352,
"strategy": "Load this script only on pages or interactions that require it; prefer dynamic import and feature-level bundles.",
"url": "https://f.vimeocdn.com/p/4.46.43/js/player.module.js",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 34 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 34 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 320 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 320 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "largest-contentful-paint",
"title": "Largest Contentful Paint",
"description": "Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)",
"score": 0.85,
"displayValue": "2.7 s",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "1",
"title": "Set goals based on performance and energy impact",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact",
"subheading": "Account for the difference in energy intensity that different types of content may have on a project and set goals based on what you would like to achieve."
},
"assessor": "script",
"issueTemplate": "## Improve Largest Contentful Paint\n\n- Lighthouse audit: largest-contentful-paint\n- Current value: 2.7 s\n- WSG guideline: 1 Set goals based on performance and energy impact\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact\n\n### Why this matters\nLargest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/standards/about/",
"status": "ok",
"finalUrl": "https://www.w3.org/standards/about/",
"performanceScore": 0.99,
"bestPracticesScore": 1,
"transferBytes": 101870,
"co2Grams": 0.039024502218,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "About W3C web standards | Web Standards | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "This page explains more about W3C web standards, including the value of creating open web standards at the World Wide Web Consortium.",
"robots": "",
"canonical": "",
"ogTitle": "About W3C web standards",
"ogDescription": "This page explains more about W3C web standards, including the value of creating open web standards at the World Wide Web Consortium.",
"ogType": "website",
"ogUrl": "https://www.w3.org/standards/about/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 29,
"tabletSmallTapTargets": 30,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 29,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 30,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 29 small targets on mobile and 30 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142481",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed5072ce1c956-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:11:41 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f013e76eb25ae6d",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 6,
"urgency": "low",
"totalEstimatedSavingsBytes": 6129,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 6129,
"totalEstimatedBlockingMs": 589,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 589,
"displayValue": "Est savings of 590 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 589 ms."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 93026
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 90.85 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 90.85 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 0,
"urgency": "low",
"transferBytes": 101870,
"css": {
"unusedBytes": 0,
"ratio": 0,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 6,
"urgency": "medium",
"transferBytes": 101870,
"estimatedDeferrableBytes": 0,
"renderBlockingMs": 589,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 0
},
"candidates": [
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 589,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 3,
"urgency": "low",
"transferBytes": 101870,
"estimatedRedundantBytes": 0,
"redundancyRatio": 0,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [],
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 101870,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 590 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 590 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/TR/",
"status": "ok",
"finalUrl": "https://www.w3.org/TR/",
"performanceScore": 0.94,
"bestPracticesScore": 1,
"transferBytes": 251481,
"co2Grams": 0.09633769355340002,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 46.666666666666664,
"urgency": "medium",
"pageElementOccurrences": 29,
"uniqueElementsAssessed": 3,
"reusedFromCacheCount": 0,
"components": [
{
"signature": "search|get|self|input|search|filter-tr-name|no-autocomplete|optional|no-pattern|no-minlength",
"role": "search",
"controlType": "search",
"fieldName": "filter-tr-name",
"formContext": "search|get|self",
"hasLabel": true,
"hasValidationRule": false,
"hasErrorMessagingHook": true,
"toolingFriendly": false,
"assessment": {
"score": 40,
"urgency": "medium",
"issues": [
"No explicit validation rule",
"Missing autocomplete for tooling support"
],
"recommendations": [
"Define validation constraints (required, pattern, min/max, or semantic input type).",
"Provide meaningful autocomplete values to support browsers and assistive tooling."
]
},
"reusedFromCache": false
},
{
"signature": "search|get|self|input|checkbox|status[]|no-autocomplete|optional|no-pattern|no-minlength",
"role": "search",
"controlType": "checkbox",
"fieldName": "status[]",
"formContext": "search|get|self",
"hasLabel": true,
"hasValidationRule": false,
"hasErrorMessagingHook": false,
"toolingFriendly": true,
"assessment": {
"score": 50,
"urgency": "medium",
"issues": [
"No explicit validation rule",
"No error messaging hook"
],
"recommendations": [
"Define validation constraints (required, pattern, min/max, or semantic input type).",
"Add aria-errormessage/aria-describedby and a visible error region for invalid input."
]
},
"reusedFromCache": false
},
{
"signature": "search|get|self|input|checkbox|tags[]|no-autocomplete|optional|no-pattern|no-minlength",
"role": "search",
"controlType": "checkbox",
"fieldName": "tags[]",
"formContext": "search|get|self",
"hasLabel": true,
"hasValidationRule": false,
"hasErrorMessagingHook": false,
"toolingFriendly": true,
"assessment": {
"score": 50,
"urgency": "medium",
"issues": [
"No explicit validation rule",
"No error messaging hook"
],
"recommendations": [
"Define validation constraints (required, pattern, min/max, or semantic input type).",
"Add aria-errormessage/aria-describedby and a visible error region for invalid input."
]
},
"reusedFromCache": false
}
],
"recommendations": [
{
"title": "No explicit validation rule",
"urgency": "medium",
"detail": "3 unique form control signature(s) on this page include this issue."
},
{
"title": "No error messaging hook",
"urgency": "medium",
"detail": "2 unique form control signature(s) on this page include this issue."
},
{
"title": "Missing autocomplete for tooling support",
"urgency": "medium",
"detail": "1 unique form control signature(s) on this page include this issue."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "W3C standards and drafts | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "The World Wide Web Consortium (W3C) is an international community where Member organizations, a full-time staff, and the public work together to develop Web standards.",
"robots": "",
"canonical": "",
"ogTitle": "W3C standards and drafts",
"ogDescription": "The World Wide Web Consortium (W3C) is an international community where Member organizations, a full-time staff, and the public work together to develop Web standards.",
"ogType": "website",
"ogUrl": "https://www.w3.org/TR/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 3236,
"tabletSmallTapTargets": 3963,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 3236,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 3963,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 3236 small targets on mobile and 3963 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"access-control-allow-origin": "*",
"age": "3156",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "max-age=0, public, s-maxage=3600",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed5597ea3e5eb-IAD",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"date": "Thu, 23 Apr 2026 18:11:54 GMT",
"etag": "W/\"e65e57e8ac317bb34d85538a28ed0a08\"",
"last-modified": "Thu, 23 Apr 2026 16:53:26 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Accept-Encoding",
"x-backend": "sf-main",
"x-content-type-options": "nosniff",
"x-request-id": "9f0e8846ed2275e5"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 10,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 95185,
"totalEstimatedBlockingMs": 756,
"opportunities": [
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 70102,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 68 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 756,
"displayValue": "Est savings of 760 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 68.46 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 756 ms."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 149094
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 145.60 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 145.60 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 12,
"urgency": "medium",
"transferBytes": 251481,
"css": {
"unusedBytes": 70102,
"ratio": 0.2787566456312803,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0.125,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "high",
"estimatedSavingsBytes": 70102,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 13,
"urgency": "medium",
"transferBytes": 251481,
"estimatedDeferrableBytes": 70102,
"renderBlockingMs": 756,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 70102
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 70102,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 756,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 33,
"urgency": "medium",
"transferBytes": 251481,
"estimatedRedundantBytes": 70102,
"redundancyRatio": 0.2787566456312803,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 70102,
"displayValue": "Est savings of 68 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 70102,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
{
"title": "Reduce DOM complexity and redundant markup",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"auditId": "dom-size",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 251481,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 68 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 68 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 760 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 760 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "largest-contentful-paint",
"title": "Largest Contentful Paint",
"description": "Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)",
"score": 0.85,
"displayValue": "2.7 s",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "1",
"title": "Set goals based on performance and energy impact",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact",
"subheading": "Account for the difference in energy intensity that different types of content may have on a project and set goals based on what you would like to achieve."
},
"assessor": "script",
"issueTemplate": "## Improve Largest Contentful Paint\n\n- Lighthouse audit: largest-contentful-paint\n- Current value: 2.7 s\n- WSG guideline: 1 Set goals based on performance and energy impact\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact\n\n### Why this matters\nLargest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "dom-size",
"title": "Avoid an excessive DOM size",
"description": "A large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).",
"score": 0.5,
"displayValue": "21,927 elements",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Avoid an excessive DOM size\n\n- Lighthouse audit: dom-size\n- Current value: 21,927 elements\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nA large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/standards/types/",
"status": "ok",
"finalUrl": "https://www.w3.org/standards/types/",
"performanceScore": 0.99,
"bestPracticesScore": 1,
"transferBytes": 123227,
"co2Grams": 0.0472059716778,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Types of documents W3C publishes | Web Standards | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Understand the differences between the various types of documents published at W3C and what each stage of maturity implies.",
"robots": "",
"canonical": "",
"ogTitle": "Types of documents W3C publishes",
"ogDescription": "Understand the differences between the various types of documents published at W3C and what each stage of maturity implies.",
"ogType": "website",
"ogUrl": "https://www.w3.org/standards/types/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 35,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 43,
"tabletSmallTapTargets": 43,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 1,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 1,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 625,
"viewportHeight": 1353,
"contentWidth": 625,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 43,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 1
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 43,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 43 small targets on mobile and 43 on tablet."
},
{
"title": "Make grid layouts breakpoint-aware",
"urgency": "medium",
"detail": "1 grid container(s) overflowed across tested viewports (1 on mobile, 0 on tablet). Use intrinsic tracks (minmax(), fr), wrapping, and breakpoint-aware grid templates."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142424",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed59b8a08e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:12:05 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f01406949e5a29d",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 5,
"urgency": "low",
"totalEstimatedSavingsBytes": 6129,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 6129,
"totalEstimatedBlockingMs": 558,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 558,
"displayValue": "Est savings of 560 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 558 ms."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 111775
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 109.16 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 109.16 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 3,
"urgency": "low",
"transferBytes": 123227,
"css": {
"unusedBytes": 0,
"ratio": 0,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0.125,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 6,
"urgency": "medium",
"transferBytes": 123227,
"estimatedDeferrableBytes": 0,
"renderBlockingMs": 558,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 0
},
"candidates": [
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 558,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 13,
"urgency": "low",
"transferBytes": 123227,
"estimatedRedundantBytes": 0,
"redundancyRatio": 0,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [],
"recommendations": [
{
"title": "Reduce DOM complexity and redundant markup",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"auditId": "dom-size",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 123227,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 560 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 560 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "dom-size",
"title": "Avoid an excessive DOM size",
"description": "A large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).",
"score": 0.5,
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"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Avoid an excessive DOM size\n\n- Lighthouse audit: dom-size\n- Current value: 823 elements\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nA large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/groups/",
"status": "ok",
"finalUrl": "https://www.w3.org/groups/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 157451,
"co2Grams": 0.0603165495114,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Discover W3C groups | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "A variety of W3C groups enable W3C to pursue its mission through the creation of Web standards, guidelines, and supporting materials. Community and Business Groups offer more ways for innovators to bring work to W3C.",
"robots": "",
"canonical": "",
"ogTitle": "Discover W3C groups",
"ogDescription": "A variety of W3C groups enable W3C to pursue its mission through the creation of Web standards, guidelines, and supporting materials. Community and Business Groups offer more ways for innovators to bring work to W3C.",
"ogType": "website",
"ogUrl": "https://www.w3.org/groups/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 12,
"tabletSmallTapTargets": 12,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
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"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
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"fixedWidthOffenders": 0,
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},
{
"device": "tablet",
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"smallTapTargets": 12,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 12 small targets on mobile and 12 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "51294",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed5cecc4ce5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:12:13 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f09f1801bfbe5ff",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
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"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 16,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60704,
"totalEstimatedBlockingMs": 1202,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1202,
"displayValue": "Est savings of 1,200 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35621,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1202 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.79 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 149095
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 145.60 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 145.60 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 8,
"urgency": "low",
"transferBytes": 157451,
"css": {
"unusedBytes": 35621,
"ratio": 0.22623546373157363,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35621,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 17,
"urgency": "high",
"transferBytes": 157451,
"estimatedDeferrableBytes": 35621,
"renderBlockingMs": 1202,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35621
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35621,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1202,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 20,
"urgency": "low",
"transferBytes": 157451,
"estimatedRedundantBytes": 35621,
"redundancyRatio": 0.22623546373157363,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35621,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35621,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 157451,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,200 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,200 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/translations/",
"status": "ok",
"finalUrl": "https://www.w3.org/Translations/",
"performanceScore": 0.98,
"bestPracticesScore": 0.96,
"transferBytes": 78174,
"co2Grams": 0.029947005363600003,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 35,
"urgency": "medium",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": false,
"hasCanonical": false,
"hasOpenGraphCore": false,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Translations of W3C standards and drafts",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1, initial-scale = 1.0, shrink-to-fit=no",
"description": "",
"robots": "",
"canonical": "",
"ogTitle": "Translations of W3C standards and drafts",
"ogDescription": "List of translated W3C Recommendations (authorized and volunteer translations)",
"ogType": "",
"ogUrl": "",
"twitterCard": "summary",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
},
{
"title": "Add meta description",
"urgency": "medium",
"detail": "Provide a concise description to improve machine interpretation and preview quality."
},
{
"title": "Complete Open Graph metadata",
"urgency": "medium",
"detail": "Include og:title, og:description, og:type, and og:url for robust machine-readable sharing metadata."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 930,
"tabletSmallTapTargets": 1132,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 0,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
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"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 930,
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},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
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"smallTapTargets": 1132,
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}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 930 small targets on mobile and 1132 on tablet."
}
]
},
"securityLight": {
"score": 29,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": false,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"access-control-allow-origin": "*",
"age": "55",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "max-age=600, s-maxage=2592001",
"cf-cache-status": "BYPASS",
"cf-ray": "9f0ed5e06e08e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=utf-8",
"date": "Thu, 23 Apr 2026 18:12:16 GMT",
"expires": "Thu, 23 Apr 2026 17:48:16 GMT",
"last-modified": "Mon, 20 Apr 2026 06:12:21 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"vary": "Accept-Encoding",
"via": "1.1 varnish",
"x-backend": "www-mirrors",
"x-cache": "HIT",
"x-cache-hits": "1",
"x-content-type-options": "nosniff",
"x-fastly-request-id": "7b6a5cf7c40f7c8568ce1e91778bd454a84c1672",
"x-github-request-id": "72D8:1BD9:27B0182:2ACE09C:69EA5908",
"x-proxy-cache": "MISS",
"x-request-id": "9f0ed5e06e08e5eb",
"x-served-by": "cache-iad-kcgs7200036-IAD",
"x-timer": "S1776967936.119838,VS0,VE2"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Enable Strict-Transport-Security",
"urgency": "medium",
"detail": "Set a Strict-Transport-Security header to enforce HTTPS on repeat visits."
},
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 50,
"urgency": "medium",
"checks": {
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"totalImages": 2,
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"imagesWithoutLazy": 2
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "2 of 2 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 70,
"urgency": "medium",
"data": {
"hasPrintStyles": false,
"hasReducedMotion": false,
"media": {
"totalImages": 2,
"lazyImages": 0,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "Helvetica, sans-serif",
"usesSystemFont": true
},
"tracking": {
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},
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"hasMainContent": true
}
},
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{
"guideline": "17.1",
"title": "Missing print style sheet",
"urgency": "low",
"detail": "Add a @media print stylesheet to ensure the page is optimized for paper-saving printing.",
"wsid": "17.printed documents",
"assessor": "script",
"example": "@media print {\n /* Hide non-critical navigation and backgrounds */\n nav, .ads, header, footer { display: none; }\n body { font-size: 12pt; color: #000; background: #fff; }\n a::after { content: \" (\" attr(href) \") \"; } /* Show URLs */\n}"
},
{
"guideline": "12.3",
"title": "No reduced motion support",
"urgency": "low",
"detail": "Implement prefers-reduced-motion to allow users to disable animations, reducing compute and improving accessibility.",
"wsid": "12.control animation",
"assessor": "script",
"example": "@media (prefers-reduced-motion: reduce) {\n *, ::before, ::after {\n animation-duration: 0.01ms !important;\n animation-iteration-count: 1 !important;\n transition-duration: 0.01ms !important;\n scroll-behavior: auto !important;\n }\n}"
},
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 0/2 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 0,
"urgency": "low",
"totalEstimatedSavingsBytes": 0,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [],
"recommendations": [
{
"title": "No major compression opportunity detected",
"urgency": "low",
"detail": "Compression signals look healthy in current Lighthouse audits; continue enforcing compression and asset encoding in CI/CD."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 0,
"urgency": "low",
"totalEstimatedSavingsBytes": 0,
"totalEstimatedBlockingMs": 0,
"opportunities": [],
"recommendations": [
{
"title": "No obvious optimization bloat signals",
"urgency": "low",
"detail": "No major easy-win optimization opportunities were detected from current Lighthouse signals."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 35172.119646182495
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 34.35 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 34.35 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 5,
"urgency": "low",
"transferBytes": 78174,
"css": {
"unusedBytes": 0,
"ratio": 0,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0.25,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 0,
"urgency": "low",
"transferBytes": 78174,
"estimatedDeferrableBytes": 0,
"renderBlockingMs": 0,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 0
},
"candidates": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 20,
"urgency": "low",
"transferBytes": 78174,
"estimatedRedundantBytes": 0,
"redundancyRatio": 0,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [],
"recommendations": [
{
"title": "Reduce DOM complexity and redundant markup",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"auditId": "dom-size",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 78174,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "dom-size",
"title": "Avoid an excessive DOM size",
"description": "A large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).",
"score": 0,
"displayValue": "3,708 elements",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Avoid an excessive DOM size\n\n- Lighthouse audit: dom-size\n- Current value: 3,708 elements\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nA large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0.5,
"displayValue": "Est savings of 0 ms",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 0 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/standards/review/",
"status": "ok",
"finalUrl": "https://www.w3.org/standards/review/",
"performanceScore": 0.99,
"bestPracticesScore": 1,
"transferBytes": 105774,
"co2Grams": 0.040520052003599996,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Reviews and public feedback | Web Standards | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Public review and feedback on specifications, implementations, test suites, code.",
"robots": "",
"canonical": "",
"ogTitle": "Reviews and public feedback",
"ogDescription": "Public review and feedback on specifications, implementations, test suites, code.",
"ogType": "website",
"ogUrl": "https://www.w3.org/standards/review/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 35,
"tabletSmallTapTargets": 35,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 35,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 35,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 35 small targets on mobile and 35 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142268",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed63f7db5e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:12:31 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f0144e52c351f27",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 33,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 7,
"imagesWithLazy": 2,
"imagesWithoutLazy": 5
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "5 of 7 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 7,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/7 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 6,
"urgency": "low",
"totalEstimatedSavingsBytes": 6129,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 6129,
"totalEstimatedBlockingMs": 409,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 409,
"displayValue": "Est savings of 410 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 409 ms."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 93385.32402234637
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 91.20 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 91.20 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 0,
"urgency": "low",
"transferBytes": 105774,
"css": {
"unusedBytes": 0,
"ratio": 0,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 4,
"urgency": "medium",
"transferBytes": 105774,
"estimatedDeferrableBytes": 0,
"renderBlockingMs": 409,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 0
},
"candidates": [
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 409,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 5,
"urgency": "low",
"transferBytes": 105774,
"estimatedRedundantBytes": 0,
"redundancyRatio": 0,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [],
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 105774,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 410 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 410 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/get-involved/promote/",
"status": "ok",
"finalUrl": "https://www.w3.org/get-involved/promote/",
"performanceScore": 0.96,
"bestPracticesScore": 1,
"transferBytes": 194794,
"co2Grams": 0.07462195823160002,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Promote web standards | Get involved | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "This page describes the ways individuals and organizations can promote web standardization",
"robots": "",
"canonical": "",
"ogTitle": "Promote web standards",
"ogDescription": "This page describes the ways individuals and organizations can promote web standardization",
"ogType": "website",
"ogUrl": "https://www.w3.org/get-involved/promote/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 24,
"tabletSmallTapTargets": 25,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 24,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 25,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 24 small targets on mobile and 25 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142529",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed67399c0e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:12:39 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f013eb93d62d262",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 30,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 6,
"imagesWithLazy": 2,
"imagesWithoutLazy": 4
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "4 of 6 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 6,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/6 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 13,
"urgency": "low",
"totalEstimatedSavingsBytes": 25084,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6130,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60905,
"totalEstimatedBlockingMs": 1189,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1189,
"displayValue": "Est savings of 1,190 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35821,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6130,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1189 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.98 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 186914
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 182.53 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 182.53 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 6,
"urgency": "low",
"transferBytes": 194794,
"css": {
"unusedBytes": 35821,
"ratio": 0.1838917009764161,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35821,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 16,
"urgency": "high",
"transferBytes": 194794,
"estimatedDeferrableBytes": 35821,
"renderBlockingMs": 1189,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35821
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35821,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1189,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 18,
"urgency": "low",
"transferBytes": 194794,
"estimatedRedundantBytes": 35821,
"redundancyRatio": 0.1838917009764161,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35821,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35821,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 194794,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,190 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,190 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/liaisons/",
"status": "ok",
"finalUrl": "https://www.w3.org/liaisons/",
"performanceScore": 0.96,
"bestPracticesScore": 1,
"transferBytes": 186014,
"co2Grams": 0.0712585035396,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Liaisons | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "W3C coordinates the development of standards for the Internet or the Web through liaisons with national, regional and international organizations.",
"robots": "",
"canonical": "",
"ogTitle": "Liaisons",
"ogDescription": "W3C coordinates the development of standards for the Internet or the Web through liaisons with national, regional and international organizations.",
"ogType": "website",
"ogUrl": "https://www.w3.org/liaisons/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 35,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 249,
"tabletSmallTapTargets": 259,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 1,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 1,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 708,
"viewportHeight": 1533,
"contentWidth": 708,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 249,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 1
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 259,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 249 small targets on mobile and 259 on tablet."
},
{
"title": "Make grid layouts breakpoint-aware",
"urgency": "medium",
"detail": "1 grid container(s) overflowed across tested viewports (1 on mobile, 0 on tablet). Use intrinsic tracks (minmax(), fr), wrapping, and breakpoint-aware grid templates."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142284",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed6a9c8bde5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:12:48 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f0144ea9f9d1f27",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 13,
"urgency": "low",
"totalEstimatedSavingsBytes": 25084,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6130,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60838,
"totalEstimatedBlockingMs": 1153,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1153,
"displayValue": "Est savings of 1,150 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35754,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6130,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1153 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.92 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 167852
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 163.92 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 163.92 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 9,
"urgency": "low",
"transferBytes": 186014,
"css": {
"unusedBytes": 35754,
"ratio": 0.19221133893147826,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0.125,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35754,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 15,
"urgency": "high",
"transferBytes": 186014,
"estimatedDeferrableBytes": 35754,
"renderBlockingMs": 1153,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35754
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35754,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1153,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 28,
"urgency": "low",
"transferBytes": 186014,
"estimatedRedundantBytes": 35754,
"redundancyRatio": 0.19221133893147826,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35754,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35754,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
{
"title": "Reduce DOM complexity and redundant markup",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"auditId": "dom-size",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 186014,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,150 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,150 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "dom-size",
"title": "Avoid an excessive DOM size",
"description": "A large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).",
"score": 0.5,
"displayValue": "1,311 elements",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Avoid an excessive DOM size\n\n- Lighthouse audit: dom-size\n- Current value: 1,311 elements\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nA large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow). [Learn how to avoid an excessive DOM size](https://developer.chrome.com/docs/lighthouse/performance/dom-size/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/groups/other/tag/",
"status": "ok",
"finalUrl": "https://www.w3.org/groups/other/tag/",
"performanceScore": 0.86,
"bestPracticesScore": 1,
"transferBytes": 300777,
"co2Grams": 0.11522207424780001,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Technical Architecture Group | Discover W3C groups | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "The TAG is a special working group within the W3C, chartered (under the W3C Process Document) with stewardship of the web architecture.
\n\nAs outlined by the Process Document, there are three aspects to this mission:
\n\n- to document and build consensus around principles of web architecture and to interpret and clarify these principles when necessary;
\n- to resolve issues involving general web architecture brought to the TAG;
\n- to help coordinate cross-technology architecture developments inside and outside W3C.
\n
",
"robots": "",
"canonical": "",
"ogTitle": "Technical Architecture Group",
"ogDescription": "The TAG is a special working group within the W3C, chartered (under the W3C Process Document) with stewardship of the web architecture.
\n\nAs outlined by the Process Document, there are three aspects to this mission:
\n\n- to document and build consensus around principles of web architecture and to interpret and clarify these principles when necessary;
\n- to resolve issues involving general web architecture brought to the TAG;
\n- to help coordinate cross-technology architecture developments inside and outside W3C.
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",
"ogType": "website",
"ogUrl": "https://www.w3.org/groups/other/tag/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 13,
"tabletSmallTapTargets": 13,
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},
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{
"device": "mobile",
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},
{
"device": "tablet",
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"smallTapTargets": 13,
"oversizedMedia": 0,
"gridContainersDetected": 4,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 13 small targets on mobile and 13 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "no-cache, private",
"cf-cache-status": "BYPASS",
"cf-ray": "9f0ed6e09b5ae5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:12:57 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Accept-Encoding",
"x-backend": "sf-main",
"x-content-type-options": "nosniff",
"x-request-id": "9f0ed6e09b5ae5eb"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 30,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 6,
"imagesWithLazy": 2,
"imagesWithoutLazy": 4
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "4 of 6 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 6,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/6 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
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"detected": false,
"signals": {
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"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 2,
"urgency": "low",
"totalEstimatedSavingsBytes": 6129,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 41329,
"totalEstimatedBlockingMs": 2067,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 2067,
"displayValue": "Est savings of 2,070 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35200,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 34 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 2067 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.38 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 97137
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 94.86 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 94.86 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 4,
"urgency": "low",
"transferBytes": 300777,
"css": {
"unusedBytes": 35200,
"ratio": 0.11703022505045266,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35200,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 17,
"urgency": "high",
"transferBytes": 300777,
"estimatedDeferrableBytes": 35200,
"renderBlockingMs": 2067,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35200
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35200,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 2067,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy font from www.w3.org",
"area": "font",
"urgency": "medium",
"estimatedSavingsBytes": 156920,
"url": "https://www.w3.org/_sf/build/fonts/fa-solid-900.fb8184ad.woff2",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 9,
"urgency": "low",
"transferBytes": 300777,
"estimatedRedundantBytes": 35200,
"redundancyRatio": 0.11703022505045266,
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"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
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"displayValue": "Est savings of 34 KiB"
}
],
"recommendations": [
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"title": "Reduce unused css",
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"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 22,
"urgency": "low",
"totalTransferBytes": 300777,
"heavyRequestCount": 1,
"heavyBytes": 156920,
"heavyRatio": 0.5217154237192339,
"heavyRequests": [
{
"url": "https://www.w3.org/_sf/build/fonts/fa-solid-900.fb8184ad.woff2",
"transferSize": 156920,
"resourceType": "font",
"mimeType": "font/woff2",
"domain": "www.w3.org"
}
],
"groupedByType": [
{
"resourceType": "font",
"count": 1,
"transferBytes": 156920
}
],
"groupedByOrigin": [
{
"domain": "www.w3.org",
"count": 1,
"transferBytes": 156920
}
],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
{
"title": "Modularize heavy font asset from www.w3.org",
"urgency": "medium",
"estimatedSavingsBytes": 156920,
"strategy": "Subset or defer this font so full font payloads are only fetched when needed.",
"url": "https://www.w3.org/_sf/build/fonts/fa-solid-900.fb8184ad.woff2",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 34 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 34 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 2,070 ms",
"impact": "high",
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"categoryId": "3",
"categoryName": "Web Development",
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"title": "Use the most efficient solution for your service",
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},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 2,070 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
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"description": "Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)",
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"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "1",
"title": "Set goals based on performance and energy impact",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact",
"subheading": "Account for the difference in energy intensity that different types of content may have on a project and set goals based on what you would like to achieve."
},
"assessor": "script",
"issueTemplate": "## Improve Largest Contentful Paint\n\n- Lighthouse audit: largest-contentful-paint\n- Current value: 3.3 s\n- WSG guideline: 1 Set goals based on performance and energy impact\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact\n\n### Why this matters\nLargest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/get-involved/",
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"performanceScore": 0.99,
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"co2Grams": 0.04677692050980001,
"greenWeb": {
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"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
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"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
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},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
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}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
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}
},
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}
]
},
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"checks": {
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},
"observed": {
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]
},
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"checks": {
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},
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{
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}
]
},
"securityLight": {
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"checks": {
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},
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"date": "Thu, 23 Apr 2026 18:13:05 GMT",
"priority": "u=0,i",
"server": "cloudflare",
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"vary": "Origin,Accept-Encoding",
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},
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"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 30,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 6,
"imagesWithLazy": 2,
"imagesWithoutLazy": 4
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "4 of 6 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 6,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/6 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 5,
"urgency": "low",
"totalEstimatedSavingsBytes": 6130,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6130,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 6130,
"totalEstimatedBlockingMs": 0,
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6130,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 111498.9
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 108.89 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 108.89 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 0,
"urgency": "low",
"transferBytes": 122107,
"css": {
"unusedBytes": 0,
"ratio": 0,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 0,
"urgency": "low",
"transferBytes": 122107,
"estimatedDeferrableBytes": 0,
"renderBlockingMs": 0,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 0
},
"candidates": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 3,
"urgency": "low",
"transferBytes": 122107,
"estimatedRedundantBytes": 0,
"redundancyRatio": 0,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [],
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 122107,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": []
},
{
"url": "https://www.w3.org/ecosystems/",
"status": "ok",
"finalUrl": "https://www.w3.org/ecosystems/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 1081714,
"co2Grams": 0.41438451351960004,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Business Ecosystems | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Learn about the various business ecosystems that the web transforms and how W3C meets particular industry needs.",
"robots": "",
"canonical": "",
"ogTitle": "Business Ecosystems",
"ogDescription": "Learn about the various business ecosystems that the web transforms and how W3C meets particular industry needs.",
"ogType": "website",
"ogUrl": "https://www.w3.org/ecosystems/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 20,
"urgency": "low",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 7,
"tabletSmallTapTargets": 9,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 7,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 9,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 7 small targets on mobile and 9 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142309",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed74daaade5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:13:14 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f0144f1ca081f27",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 20,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 13,
"imagesWithLazy": 9,
"imagesWithoutLazy": 4
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 13,
"lazyImages": 9,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 9/13 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 66,
"urgency": "high",
"totalEstimatedSavingsBytes": 716523.9,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "high",
"estimatedSavingsBytes": 691440.9,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
},
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6130,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 675.24 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 1213015.9,
"totalEstimatedBlockingMs": 1198,
"opportunities": [
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 691440.9,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 675 KiB",
"urgency": "high",
"sourceAuditId": "modern-image-formats"
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 461019,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 450 KiB",
"urgency": "high",
"sourceAuditId": "uses-responsive-images"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1198,
"displayValue": "Est savings of 1,200 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35473,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6130,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 675.24 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 450.21 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1198 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.64 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 1058246.6
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 1.01 MB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 1.01 MB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 1,
"urgency": "low",
"transferBytes": 1081714,
"css": {
"unusedBytes": 35473,
"ratio": 0.03279332614720712,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35473,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 13,
"urgency": "high",
"transferBytes": 1081714,
"estimatedDeferrableBytes": 35473,
"renderBlockingMs": 1198,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35473
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35473,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1198,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "high",
"estimatedSavingsBytes": 574717,
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/payments-shutterstock_605410205-1024.png",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 9,
"urgency": "low",
"transferBytes": 1081714,
"estimatedRedundantBytes": 35473,
"redundancyRatio": 0.03279332614720712,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35473,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35473,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 28,
"urgency": "medium",
"totalTransferBytes": 1081714,
"heavyRequestCount": 2,
"heavyBytes": 710860,
"heavyRatio": 0.6571607652299961,
"heavyRequests": [
{
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/payments-shutterstock_605410205-1024.png",
"transferSize": 574717,
"resourceType": "image",
"mimeType": "image/png",
"domain": "www.w3.org"
},
{
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/data-head-shutterstock_728178127.jpg",
"transferSize": 136143,
"resourceType": "image",
"mimeType": "image/jpeg",
"domain": "www.w3.org"
}
],
"groupedByType": [
{
"resourceType": "image",
"count": 2,
"transferBytes": 710860
}
],
"groupedByOrigin": [
{
"domain": "www.w3.org",
"count": 2,
"transferBytes": 710860
}
],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
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"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 3/7 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 5,
"urgency": "low",
"totalEstimatedSavingsBytes": 65007.25,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "low",
"estimatedSavingsBytes": 39925.25,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
},
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Use modern image compression formats",
"urgency": "low",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 38.99 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 150274.25,
"totalEstimatedBlockingMs": 306,
"opportunities": [
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 50291,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 49 KiB",
"urgency": "medium",
"sourceAuditId": "uses-responsive-images"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 34976,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 34 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 306,
"displayValue": "Est savings of 310 ms",
"urgency": "medium",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 39925.25,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 39 KiB",
"urgency": "low",
"sourceAuditId": "modern-image-formats"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Right-size images for viewport",
"urgency": "medium",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 49.11 KB."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.16 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "medium",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 306 ms."
},
{
"title": "Serve images in next-gen formats",
"urgency": "low",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 38.99 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 289390.3333333333
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 282.61 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 282.61 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 1,
"urgency": "low",
"transferBytes": 1306704,
"css": {
"unusedBytes": 34976,
"ratio": 0.026766582179284674,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 34976,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 4,
"urgency": "medium",
"transferBytes": 1306704,
"estimatedDeferrableBytes": 34976,
"renderBlockingMs": 306,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 34976
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 34976,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 306,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy script from www.youtube-nocookie.com",
"area": "script",
"urgency": "high",
"estimatedSavingsBytes": 446953,
"url": "https://www.youtube-nocookie.com/s/player/8456c9de/player_embed_es6.vflset/en_US/base.js",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy script from www.youtube.com",
"area": "script",
"urgency": "high",
"estimatedSavingsBytes": 188926,
"url": "https://www.youtube.com/s/_/ytembeds/_/js/k=ytembeds.base.en_US.Jn-9HPgVKSU.2021.O/am=AAAABA/d=1/exm=base,root/ed=1/br=1/rs=AGKMywFIPd8H83JB8R7S3Dnm-hTNowb--w/m=r78Drb",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "medium",
"estimatedSavingsBytes": 100796,
"url": "https://www.w3.org/cms-uploads/_920xAUTO_crop_center-center_none/marvin-meyer-SYTO3xs06fU-unsplash.jpg",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 53,
"urgency": "medium",
"providerCount": 3,
"requestCount": 4,
"transferBytes": 803248,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [
{
"hostname": "www.youtube-nocookie.com",
"resourceType": "script",
"requestCount": 1,
"transferBytes": 446953,
"sampleUrl": "https://www.youtube-nocookie.com/s/player/8456c9de/player_embed_es6.vflset/en_US/base.js",
"greenCheck": {
"hostname": "www.youtube-nocookie.com",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Google Cloud",
"hostedByWebsite": "https://cloud.google.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-25T09:45:44",
"supportingDocuments": [
{
"id": 108,
"title": "Sustainability at Google",
"link": "https://sustainability.google"
},
{
"id": 1364,
"title": "Google 2024 Environmental Report",
"link": "https://www.gstatic.com/gumdrop/sustainability/google-2024-environmental-report.pdf"
},
{
"id": 1365,
"title": "Alphabet 2024 CDP Climate Change Response",
"link": "https://www.gstatic.com/gumdrop/sustainability/alphabet-2024-cdp-climate-change-response.pdf"
},
{
"id": 1366,
"title": "Google 2024 Supplier Responsibility Report.",
"link": "https://www.gstatic.com/gumdrop/sustainability/google-2024-supplier-responsibility-report.pdf"
},
{
"id": 1367,
"title": "Alphabet FY2023 Environmental Indicators Assurance Letter",
"link": "https://www.gstatic.com/gumdrop/sustainability/alphabet-fy2023-environmental-indicators-assurance-letter.pdf"
},
{
"id": 1368,
"title": "3Degrees Cloud Services Review Statement",
"link": "https://services.google.com/fh/files/misc/3degrees_cloud_services_review_statement_final.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.youtube-nocookie.com",
"error": null
}
},
{
"hostname": "www.youtube.com",
"resourceType": "script",
"requestCount": 2,
"transferBytes": 332605,
"sampleUrl": "https://www.youtube.com/s/_/ytembeds/_/js/k=ytembeds.base.en_US.Jn-9HPgVKSU.2021.O/am=AAAABA/d=1/br=1/rs=AGKMywFIPd8H83JB8R7S3Dnm-hTNowb--w/m=root,base",
"greenCheck": {
"hostname": "www.youtube.com",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Google Cloud",
"hostedByWebsite": "https://cloud.google.com",
"listedProvider": true,
"partner": null,
"modified": "2026-04-14T07:18:20",
"supportingDocuments": [
{
"id": 108,
"title": "Sustainability at Google",
"link": "https://sustainability.google"
},
{
"id": 1364,
"title": "Google 2024 Environmental Report",
"link": "https://www.gstatic.com/gumdrop/sustainability/google-2024-environmental-report.pdf"
},
{
"id": 1365,
"title": "Alphabet 2024 CDP Climate Change Response",
"link": "https://www.gstatic.com/gumdrop/sustainability/alphabet-2024-cdp-climate-change-response.pdf"
},
{
"id": 1366,
"title": "Google 2024 Supplier Responsibility Report.",
"link": "https://www.gstatic.com/gumdrop/sustainability/google-2024-supplier-responsibility-report.pdf"
},
{
"id": 1367,
"title": "Alphabet FY2023 Environmental Indicators Assurance Letter",
"link": "https://www.gstatic.com/gumdrop/sustainability/alphabet-fy2023-environmental-indicators-assurance-letter.pdf"
},
{
"id": 1368,
"title": "3Degrees Cloud Services Review Statement",
"link": "https://services.google.com/fh/files/misc/3degrees_cloud_services_review_statement_final.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.youtube.com",
"error": null
}
},
{
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"title": "Reduce unused CSS",
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"score": 0,
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"categoryId": "3",
"categoryName": "Web Development",
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},
{
"auditId": "render-blocking-resources",
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"score": 0,
"displayValue": "Est savings of 310 ms",
"impact": "high",
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},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 310 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
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},
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},
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},
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}
]
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]
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}
]
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"content-security-policy": "frame-ancestors 'none'; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:13:32 GMT",
"expires": "Thu, 23 Apr 2026 18:13:32 GMT",
"priority": "u=0,i",
"request-id": "9bf31ab7-43ea-40b1-89a1-b53e3ffad88a",
"server": "cloudflare",
"server-timing": "cfExtPri",
"vary": "Accept-Encoding",
"x-content-type-options": "nosniff",
"x-request-id": "9f0ed7bf9f21e5eb"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Enable Strict-Transport-Security",
"urgency": "medium",
"detail": "Set a Strict-Transport-Security header to enforce HTTPS on repeat visits."
},
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
},
{
"title": "Add SRI to external scripts",
"urgency": "medium",
"detail": "2 external script tag(s) are missing integrity attributes."
}
]
},
"expectedFiles": {
"score": 50,
"urgency": "medium",
"origin": "https://auth.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://auth.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://auth.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=UTF-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://auth.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=UTF-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://auth.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=UTF-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://auth.w3.org/favicon.ico",
"found": false,
"status": 404,
"contentType": "text/html; charset=UTF-8"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest, /favicon.ico."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 80,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": false,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "12.3",
"title": "No reduced motion support",
"urgency": "low",
"detail": "Implement prefers-reduced-motion to allow users to disable animations, reducing compute and improving accessibility.",
"wsid": "12.control animation",
"assessor": "script",
"example": "@media (prefers-reduced-motion: reduce) {\n *, ::before, ::after {\n animation-duration: 0.01ms !important;\n animation-iteration-count: 1 !important;\n transition-duration: 0.01ms !important;\n scroll-behavior: auto !important;\n }\n}"
},
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 13,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 85460,
"totalEstimatedBlockingMs": 1075,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1075,
"displayValue": "Est savings of 1,080 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 36138,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unused-javascript",
"title": "Remove unused JavaScript",
"detail": "Reduce dead JS and split bundles to avoid shipping non-critical code.",
"estimatedSavingsBytes": 24239,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 24 KiB",
"urgency": "low",
"sourceAuditId": "unused-javascript"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1075 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.29 KB."
},
{
"title": "Remove unused JavaScript",
"urgency": "low",
"detail": "Reduce dead JS and split bundles to avoid shipping non-critical code. Estimated byte savings: 23.67 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 4,
"urgency": "medium",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 2,
"recommendations": [
{
"title": "Add integrity attributes for external dependencies",
"urgency": "medium",
"detail": "2 external script dependency URL(s) are missing SRI integrity attributes."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 150875
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 147.34 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 147.34 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 12,
"urgency": "low",
"transferBytes": 193066,
"css": {
"unusedBytes": 36138,
"ratio": 0.18717951374141487,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 24239,
"duplicatedBytes": 0,
"ratio": 0.12554774015103642,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 36138,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
{
"area": "javascript",
"title": "Remove unused JavaScript and feature bundles",
"urgency": "medium",
"estimatedSavingsBytes": 24239,
"strategy": "Drop unused packages and feature code, or move them behind route-level or interaction-triggered imports.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 18,
"urgency": "high",
"transferBytes": 193066,
"estimatedDeferrableBytes": 60377,
"renderBlockingMs": 1075,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 24239,
"unusedCssSavings": 36138
},
"candidates": [
{
"title": "Defer non-critical JavaScript",
"area": "javascript",
"urgency": "medium",
"estimatedSavingsBytes": 24239,
"strategy": "Split bundles and load feature code on interaction or route transition.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 36138,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1075,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 8,
"urgency": "low",
"providerCount": 1,
"requestCount": 2,
"transferBytes": 21450,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [
{
"hostname": "www.w3.org",
"resourceType": "script",
"requestCount": 2,
"transferBytes": 21450,
"sampleUrl": "https://www.w3.org/assets/website-2021/js/libraries/fontfaceobserver.js",
"greenCheck": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
}
}
],
"recommendations": [
{
"title": "Maintain a third-party JavaScript inventory",
"urgency": "low",
"detail": "Track 1 third-party script origin(s) and assign an owner plus business justification for each."
}
]
},
"redundancy": {
"score": 25,
"urgency": "low",
"transferBytes": 193066,
"estimatedRedundantBytes": 60377,
"redundancyRatio": 0.31272725389245126,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 36138,
"displayValue": "Est savings of 35 KiB"
},
{
"auditId": "unused-javascript",
"title": "Reduce unused JavaScript",
"savingsBytes": 24239,
"displayValue": "Est savings of 24 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 36138,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
{
"title": "Reduce unused javascript",
"urgency": "medium",
"estimatedSavingsBytes": 24239,
"auditId": "unused-javascript",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 3,
"urgency": "low",
"totalTransferBytes": 193066,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,080 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,080 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "largest-contentful-paint",
"title": "Largest Contentful Paint",
"description": "Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)",
"score": 0.64,
"displayValue": "3.5 s",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "1",
"title": "Set goals based on performance and energy impact",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact",
"subheading": "Account for the difference in energy intensity that different types of content may have on a project and set goals based on what you would like to achieve."
},
"assessor": "script",
"issueTemplate": "## Improve Largest Contentful Paint\n\n- Lighthouse audit: largest-contentful-paint\n- Current value: 3.5 s\n- WSG guideline: 1 Set goals based on performance and energy impact\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact\n\n### Why this matters\nLargest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "unused-javascript",
"title": "Reduce unused JavaScript",
"description": "Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. [Learn how to reduce unused JavaScript](https://developer.chrome.com/docs/lighthouse/performance/unused-javascript/).",
"score": 0.5,
"displayValue": "Est savings of 24 KiB",
"impact": "medium",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "16",
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance",
"subheading": "Use libraries and frameworks only where necessary, when plain code or smaller packages are inappropriate for the use case, and they are kept up to date."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused JavaScript\n\n- Lighthouse audit: unused-javascript\n- Current value: Est savings of 24 KiB\n- WSG guideline: 16 Use dependencies appropriately and ensure maintenance\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance\n\n### Why this matters\nReduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. [Learn how to reduce unused JavaScript](https://developer.chrome.com/docs/lighthouse/performance/unused-javascript/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/support-us/",
"status": "ok",
"finalUrl": "https://www.w3.org/support-us/",
"performanceScore": 0.96,
"bestPracticesScore": 0.79,
"transferBytes": 183438,
"co2Grams": 0.0702716858532,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Support us | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Find out how you can make a huge difference to our operations as a public-interest non-profit, and help us to achieve our vision.",
"robots": "",
"canonical": "",
"ogTitle": "Support us",
"ogDescription": "Find out how you can make a huge difference to our operations as a public-interest non-profit, and help us to achieve our vision.",
"ogType": "website",
"ogUrl": "https://www.w3.org/support-us/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 21,
"tabletSmallTapTargets": 19,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 21,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 19,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 21 small targets on mobile and 19 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142601",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed7f62840e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:13:41 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f013e771ed9137e",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 33,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 7,
"imagesWithLazy": 2,
"imagesWithoutLazy": 5
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "5 of 7 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 7,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/7 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 14,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60494,
"totalEstimatedBlockingMs": 1043,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1043,
"displayValue": "Est savings of 1,040 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35411,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1043 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.58 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 167566.9
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 163.64 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 163.64 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 7,
"urgency": "low",
"transferBytes": 183438,
"css": {
"unusedBytes": 35411,
"ratio": 0.19304070040013518,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35411,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 14,
"urgency": "high",
"transferBytes": 183438,
"estimatedDeferrableBytes": 35411,
"renderBlockingMs": 1043,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35411
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35411,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1043,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 18,
"urgency": "low",
"transferBytes": 183438,
"estimatedRedundantBytes": 35411,
"redundancyRatio": 0.19304070040013518,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35411,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35411,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 183438,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,040 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,040 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/email/",
"status": "ok",
"finalUrl": "https://www.w3.org/email/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 176820,
"co2Grams": 0.06773645314800002,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Mailing lists | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Mailing lists",
"robots": "",
"canonical": "",
"ogTitle": "Mailing lists",
"ogDescription": "Mailing lists",
"ogType": "website",
"ogUrl": "https://www.w3.org/email/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 35,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 41,
"tabletSmallTapTargets": 41,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 1,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 1,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 430,
"viewportHeight": 931,
"contentWidth": 430,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 41,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 1
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 41,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 41 small targets on mobile and 41 on tablet."
},
{
"title": "Make grid layouts breakpoint-aware",
"urgency": "medium",
"detail": "1 grid container(s) overflowed across tested viewports (1 on mobile, 0 on tablet). Use intrinsic tracks (minmax(), fr), wrapping, and breakpoint-aware grid templates."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "51156",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed826db59e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:13:49 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f09f733f9d86908",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 14,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60822,
"totalEstimatedBlockingMs": 1177,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1177,
"displayValue": "Est savings of 1,180 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35739,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1177 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.90 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 167841
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 163.91 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 163.91 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 7,
"urgency": "low",
"transferBytes": 176820,
"css": {
"unusedBytes": 35739,
"ratio": 0.20212080081438752,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35739,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 16,
"urgency": "high",
"transferBytes": 176820,
"estimatedDeferrableBytes": 35739,
"renderBlockingMs": 1177,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35739
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35739,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1177,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 19,
"urgency": "low",
"transferBytes": 176820,
"estimatedRedundantBytes": 35739,
"redundancyRatio": 0.20212080081438752,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35739,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35739,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 176820,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,180 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,180 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/guide/",
"status": "ok",
"finalUrl": "https://www.w3.org/guide/",
"performanceScore": 0.96,
"bestPracticesScore": 1,
"transferBytes": 177287,
"co2Grams": 0.0679153521618,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 40,
"urgency": "medium",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": false,
"hasCanonical": false,
"hasOpenGraphCore": false,
"hasTwitterCard": false,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "The Art of Consensus (Guidebook)",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "",
"robots": "",
"canonical": "",
"ogTitle": "",
"ogDescription": "",
"ogType": "",
"ogUrl": "",
"twitterCard": "",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
},
{
"title": "Add meta description",
"urgency": "medium",
"detail": "Provide a concise description to improve machine interpretation and preview quality."
},
{
"title": "Complete Open Graph metadata",
"urgency": "medium",
"detail": "Include og:title, og:description, og:type, and og:url for robust machine-readable sharing metadata."
},
{
"title": "Add twitter:card metadata",
"urgency": "low",
"detail": "Include twitter card metadata to improve cross-platform machine-readable previews."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 122,
"tabletSmallTapTargets": 122,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 122,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 122,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 122 small targets on mobile and 122 on tablet."
}
]
},
"securityLight": {
"score": 29,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": false,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"access-control-allow-origin": "*",
"age": "185",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "max-age=600",
"cf-cache-status": "BYPASS",
"cf-ray": "9f0ed8389ed1e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=utf-8",
"date": "Thu, 23 Apr 2026 18:13:52 GMT",
"expires": "Thu, 23 Apr 2026 17:51:24 GMT",
"last-modified": "Sun, 19 Apr 2026 07:00:47 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"vary": "Accept-Encoding",
"via": "1.1 varnish",
"x-backend": "github-pages",
"x-cache": "HIT",
"x-cache-hits": "1",
"x-content-type-options": "nosniff",
"x-fastly-request-id": "f9aa296f25e747de8d6c6e2b4d9d1ad9e6a1da5d",
"x-github-request-id": "CA54:24C8E:36092D8:3BD0ADD:69EA59C4",
"x-proxy-cache": "MISS",
"x-request-id": "9f0ed8389ed1e5eb",
"x-served-by": "cache-iad-kcgs7200096-IAD",
"x-timer": "S1776968032.109707,VS0,VE2"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Enable Strict-Transport-Security",
"urgency": "medium",
"detail": "Set a Strict-Transport-Security header to enforce HTTPS on repeat visits."
},
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 14,
"urgency": "low",
"totalEstimatedSavingsBytes": 25082,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 61278,
"totalEstimatedBlockingMs": 1185,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1185,
"displayValue": "Est savings of 1,190 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 36196,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1185 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 35.35 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 166235
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 162.34 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 162.34 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 7,
"urgency": "low",
"transferBytes": 177287,
"css": {
"unusedBytes": 36196,
"ratio": 0.20416612611189766,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 36196,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 16,
"urgency": "high",
"transferBytes": 177287,
"estimatedDeferrableBytes": 36196,
"renderBlockingMs": 1185,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 36196
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 36196,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1185,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 19,
"urgency": "low",
"transferBytes": 177287,
"estimatedRedundantBytes": 36196,
"redundancyRatio": 0.20416612611189766,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 36196,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 36196,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 177287,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,190 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,190 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/about/positive-work-environment/",
"status": "ok",
"finalUrl": "https://www.w3.org/about/positive-work-environment/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 178848,
"co2Grams": 0.06851334222720001,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Positive Work Environment | About us | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "This page introduces W3C's Positive Work Environment",
"robots": "",
"canonical": "",
"ogTitle": "Positive Work Environment",
"ogDescription": "This page introduces W3C's Positive Work Environment",
"ogType": "website",
"ogUrl": "https://www.w3.org/about/positive-work-environment/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 22,
"tabletSmallTapTargets": 24,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 22,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 24,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 22 small targets on mobile and 24 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142625",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed88cfae9e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:14:05 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f013e7738944aff",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 14,
"urgency": "low",
"totalEstimatedSavingsBytes": 25082,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60844,
"totalEstimatedBlockingMs": 1157,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1157,
"displayValue": "Est savings of 1,160 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35762,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1157 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.92 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 170733
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 166.73 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 166.73 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 7,
"urgency": "low",
"transferBytes": 178848,
"css": {
"unusedBytes": 35762,
"ratio": 0.19995750581499375,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35762,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 16,
"urgency": "high",
"transferBytes": 178848,
"estimatedDeferrableBytes": 35762,
"renderBlockingMs": 1157,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35762
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35762,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1157,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 18,
"urgency": "low",
"transferBytes": 178848,
"estimatedRedundantBytes": 35762,
"redundancyRatio": 0.19995750581499375,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35762,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35762,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 178848,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,160 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,160 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/invited-experts/",
"status": "ok",
"finalUrl": "https://www.w3.org/invited-experts/",
"performanceScore": 0.99,
"bestPracticesScore": 1,
"transferBytes": 123899,
"co2Grams": 0.04746340237859999,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Invited Experts | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "Home page of the W3C Invited Experts, who are non-Member group participants invited by work groups for their expertise.",
"robots": "",
"canonical": "",
"ogTitle": "Invited Experts",
"ogDescription": "Home page of the W3C Invited Experts, who are non-Member group participants invited by work groups for their expertise.",
"ogType": "website",
"ogUrl": "https://www.w3.org/invited-experts/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 31,
"tabletSmallTapTargets": 36,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 31,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 36,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 31 small targets on mobile and 36 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "50988",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed8c1da04e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:14:14 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f09fbebf9380bd2",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 26,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 5,
"imagesWithLazy": 2,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "3 of 5 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 5,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/5 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 5,
"urgency": "low",
"totalEstimatedSavingsBytes": 6129,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 6129,
"totalEstimatedBlockingMs": 0,
"opportunities": [
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 113373
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 110.72 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 110.72 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 0,
"urgency": "low",
"transferBytes": 123899,
"css": {
"unusedBytes": 0,
"ratio": 0,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 0,
"urgency": "low",
"transferBytes": 123899,
"estimatedDeferrableBytes": 0,
"renderBlockingMs": 0,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 0
},
"candidates": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 3,
"urgency": "low",
"transferBytes": 123899,
"estimatedRedundantBytes": 0,
"redundancyRatio": 0,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [],
"recommendations": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 123899,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": []
},
{
"url": "https://www.w3.org/resources/",
"status": "ok",
"finalUrl": "https://www.w3.org/resources/",
"performanceScore": 0.96,
"bestPracticesScore": 1,
"transferBytes": 208321,
"co2Grams": 0.07980390032939999,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Resources | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "This page lists the various resources to help W3C Members, web developers or the public, such as mailing lists, blogs and microblogs, news, training, tutorials, tools, videos, translations, etc.",
"robots": "",
"canonical": "",
"ogTitle": "Resources",
"ogDescription": "This page lists the various resources to help W3C Members, web developers or the public, such as mailing lists, blogs and microblogs, news, training, tutorials, tools, videos, translations, etc.",
"ogType": "website",
"ogUrl": "https://www.w3.org/resources/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 26,
"urgency": "low",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 10,
"tabletSmallTapTargets": 10,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 10,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 10,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 10 small targets on mobile and 10 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142651",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed8f57d41e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:14:22 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f013e407f532fc1",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 30,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 6,
"imagesWithLazy": 2,
"imagesWithoutLazy": 4
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "4 of 6 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 6,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/6 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 12,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 60734,
"totalEstimatedBlockingMs": 1207,
"opportunities": [
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1207,
"displayValue": "Est savings of 1,210 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35651,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1207 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.82 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 197683.4
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 193.05 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 193.05 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 6,
"urgency": "low",
"transferBytes": 208321,
"css": {
"unusedBytes": 35651,
"ratio": 0.17113493118792633,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35651,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 15,
"urgency": "high",
"transferBytes": 208321,
"estimatedDeferrableBytes": 35651,
"renderBlockingMs": 1207,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35651
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35651,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1207,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 17,
"urgency": "low",
"transferBytes": 208321,
"estimatedRedundantBytes": 35651,
"redundancyRatio": 0.17113493118792633,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35651,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35651,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 0,
"urgency": "low",
"totalTransferBytes": 208321,
"heavyRequestCount": 0,
"heavyBytes": 0,
"heavyRatio": 0,
"heavyRequests": [],
"groupedByType": [],
"groupedByOrigin": [],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,210 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,210 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/developers/",
"status": "ok",
"finalUrl": "https://www.w3.org/developers/",
"performanceScore": 0.78,
"bestPracticesScore": 1,
"transferBytes": 896714,
"co2Grams": 0.34351445451960005,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Developers | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "The one-stop place to find the information and tools you need to help you learn, build, and move the Web forward.",
"robots": "",
"canonical": "",
"ogTitle": "Developers",
"ogDescription": "The one-stop place to find the information and tools you need to help you learn, build, and move the Web forward.",
"ogType": "website",
"ogUrl": "https://www.w3.org/developers/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 15,
"tabletSmallTapTargets": 16,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 15,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 16,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "medium",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 15 small targets on mobile and 16 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "142659",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed929fab1e5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:14:30 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f013e4328a4ca5e",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 33,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 7,
"imagesWithLazy": 2,
"imagesWithoutLazy": 5
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "5 of 7 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 7,
"lazyImages": 2,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 2/7 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 78,
"urgency": "high",
"totalEstimatedSavingsBytes": 695632.4,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "high",
"estimatedSavingsBytes": 670549.4,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
},
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18953,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6130,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 654.83 KB."
},
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 1134337.4,
"totalEstimatedBlockingMs": 1212,
"opportunities": [
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 670549.4,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 655 KiB",
"urgency": "high",
"sourceAuditId": "modern-image-formats"
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 403219,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 394 KiB",
"urgency": "high",
"sourceAuditId": "uses-responsive-images"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1212,
"displayValue": "Est savings of 1,210 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35486,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18953,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6130,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 654.83 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 393.77 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1212 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.65 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 274517.7237430167
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 268.08 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 268.08 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 1,
"urgency": "low",
"transferBytes": 896714,
"css": {
"unusedBytes": 35486,
"ratio": 0.039573375680540285,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 35486,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 13,
"urgency": "high",
"transferBytes": 896714,
"estimatedDeferrableBytes": 35486,
"renderBlockingMs": 1212,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 35486
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 35486,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "high",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1212,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "high",
"estimatedSavingsBytes": 673620,
"url": "https://www.w3.org/comm/assets/graphics/w3cx-accessibility-intro-twitter-only.png",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 10,
"urgency": "low",
"transferBytes": 896714,
"estimatedRedundantBytes": 35486,
"redundancyRatio": 0.039573375680540285,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 35486,
"displayValue": "Est savings of 35 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 35486,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 31,
"urgency": "medium",
"totalTransferBytes": 896714,
"heavyRequestCount": 1,
"heavyBytes": 673620,
"heavyRatio": 0.7512094157111409,
"heavyRequests": [
{
"url": "https://www.w3.org/comm/assets/graphics/w3cx-accessibility-intro-twitter-only.png",
"transferSize": 673620,
"resourceType": "image",
"mimeType": "image/png",
"domain": "www.w3.org"
}
],
"groupedByType": [
{
"resourceType": "image",
"count": 1,
"transferBytes": 673620
}
],
"groupedByOrigin": [
{
"domain": "www.w3.org",
"count": 1,
"transferBytes": 673620
}
],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "high",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
{
"title": "Modularize heavy image asset from www.w3.org",
"urgency": "high",
"estimatedSavingsBytes": 673620,
"strategy": "Serve a smaller placeholder first and load this asset only when the user scrolls to or requests the component.",
"url": "https://www.w3.org/comm/assets/graphics/w3cx-accessibility-intro-twitter-only.png",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "largest-contentful-paint",
"title": "Largest Contentful Paint",
"description": "Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)",
"score": 0.17,
"displayValue": "5.7 s",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "1",
"title": "Set goals based on performance and energy impact",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact",
"subheading": "Account for the difference in energy intensity that different types of content may have on a project and set goals based on what you would like to achieve."
},
"assessor": "script",
"issueTemplate": "## Improve Largest Contentful Paint\n\n- Lighthouse audit: largest-contentful-paint\n- Current value: 5.7 s\n- WSG guideline: 1 Set goals based on performance and energy impact\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#set-goals-based-on-performance-and-energy-impact\n\n### Why this matters\nLargest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"description": "Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).",
"score": 0,
"displayValue": "Est savings of 35 KiB",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
},
"assessor": "script",
"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "modern-image-formats",
"title": "Serve images in next-gen formats",
"description": "Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).",
"score": 0,
"displayValue": "Est savings of 655 KiB",
"impact": "high",
"wsg": {
"categoryId": "2",
"categoryName": "User Experience Design",
"id": "11",
"title": "Optimize media to reduce resource use",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use",
"subheading": "Ensure all media - including audio, video, animation, images, and other novel formats, when deemed necessary in the design, are optimized, correctly sized and formatted, use lazy loading where appropriate, with a usage policy in place."
},
"assessor": "script",
"issueTemplate": "## Improve Serve images in next-gen formats\n\n- Lighthouse audit: modern-image-formats\n- Current value: Est savings of 655 KiB\n- WSG guideline: 11 Optimize media to reduce resource use\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#optimize-media-to-reduce-resource-use\n\n### Why this matters\nImage formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats](https://developer.chrome.com/docs/lighthouse/performance/uses-webp-images/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
},
{
"auditId": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"description": "Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).",
"score": 0,
"displayValue": "Est savings of 1,210 ms",
"impact": "high",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "18",
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service",
"subheading": "Identify the project requirements, use the most efficient approach, aim for static over dynamic where possible, and consider the impact of extensions and components."
},
"assessor": "script",
"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,210 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
}
]
},
{
"url": "https://www.w3.org/developers/tools/",
"status": "ok",
"finalUrl": "https://www.w3.org/developers/tools/",
"performanceScore": 0.97,
"bestPracticesScore": 1,
"transferBytes": 176868,
"co2Grams": 0.06775484105520001,
"greenWeb": {
"page": {
"hostname": "www.w3.org",
"checked": true,
"status": "green",
"green": true,
"hostedBy": "Cloudflare",
"hostedByWebsite": "https://www.cloudflare.com",
"listedProvider": true,
"partner": null,
"modified": "2025-11-24T08:50:00",
"supportingDocuments": [
{
"id": 18,
"title": "Blog post - The Climate and Cloudflare",
"link": "https://blog.cloudflare.com/the-climate-and-cloudflare/"
},
{
"id": 1264,
"title": "Cloudflare 2023 Emissions Inventory",
"link": "https://media.greenweb.org/uploads/Cloudflare_2023_Emissions_Inventory.pdf"
}
],
"source": "https://api.thegreenwebfoundation.org/api/v3/greencheck/www.w3.org",
"error": null
},
"externalAssets": [],
"summary": {
"pageStatus": "green",
"externalOriginCount": 0,
"greenCount": 1,
"notGreenCount": 0,
"unknownCount": 0
}
},
"formValidation": {
"score": 0,
"urgency": "low",
"pageElementOccurrences": 0,
"uniqueElementsAssessed": 0,
"reusedFromCacheCount": 0,
"components": [],
"recommendations": [
{
"title": "No major form validation risks detected",
"urgency": "low",
"detail": "Continue testing form flows to ensure error handling remains clear across templates."
}
]
},
"metadata": {
"score": 10,
"urgency": "low",
"checks": {
"hasTitle": true,
"hasLang": true,
"hasDescription": true,
"hasCanonical": false,
"hasOpenGraphCore": true,
"hasTwitterCard": true,
"hasViewport": true,
"hasCharset": true,
"hasValidStructuredData": true,
"hasInvalidStructuredData": false
},
"observed": {
"title": "Validators and tools | Developers | W3C",
"lang": "en",
"charset": "utf-8",
"viewport": "width=device-width, initial-scale=1",
"description": "This page lists the validators and web developer tools.",
"robots": "",
"canonical": "",
"ogTitle": "Validators and tools",
"ogDescription": "This page lists the validators and web developer tools.",
"ogType": "website",
"ogUrl": "https://www.w3.org/developers/tools/",
"twitterCard": "summary_large_image",
"ldJsonCount": 0,
"validLdJsonCount": 0,
"invalidLdJsonCount": 0
},
"recommendations": [
{
"title": "Add canonical URL metadata",
"urgency": "medium",
"detail": "Use rel=canonical to reduce duplicate URL ambiguity for crawlers and tooling."
}
]
},
"layoutAdaptation": {
"score": 30,
"urgency": "medium",
"checks": {
"testedMobile": true,
"testedTablet": true,
"horizontalOverflowOnMobile": false,
"horizontalOverflowOnTablet": false,
"mobileSmallTapTargets": 25,
"tabletSmallTapTargets": 25,
"fixedWidthOffenders": 0,
"oversizedMedia": 0,
"gridContainersDetected": 2,
"mobileGridOverflowContainers": 0,
"tabletGridOverflowContainers": 0,
"gridOverflowContainers": 0,
"scanErrors": 0
},
"perDevice": [
{
"device": "mobile",
"viewportWidth": 390,
"viewportHeight": 844,
"contentWidth": 390,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 25,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
},
{
"device": "tablet",
"viewportWidth": 820,
"viewportHeight": 1180,
"contentWidth": 820,
"horizontalOverflowPx": 0,
"hasHorizontalOverflow": false,
"fixedWidthOffenders": 0,
"smallTapTargets": 25,
"oversizedMedia": 0,
"gridContainersDetected": 1,
"gridOverflowContainers": 0
}
],
"recommendations": [
{
"title": "Increase touch target sizes",
"urgency": "high",
"detail": "Ensure interactive controls are at least 44x44 CSS px. Detected 25 small targets on mobile and 25 on tablet."
}
]
},
"securityLight": {
"score": 14,
"urgency": "low",
"checks": {
"isHttps": true,
"hasHsts": true,
"hasCsp": true,
"hasXContentTypeOptions": true,
"hasReferrerPolicy": false,
"hasPermissionsPolicy": false,
"exposesServerFingerprint": true,
"externalScriptCount": 0,
"externalScriptsWithoutIntegrity": 0,
"vulnerableLibraryCount": 0
},
"observed": {
"headers": {
"age": "44558",
"alt-svc": "h3=\":443\"; ma=86400",
"cache-control": "public, s-maxage=7776000",
"cf-cache-status": "HIT",
"cf-ray": "9f0ed95de96ae5eb-IAD",
"content-encoding": "br",
"content-security-policy": "frame-ancestors 'self' https://cms.w3.org/ https://cms-dev.w3.org/; upgrade-insecure-requests",
"content-type": "text/html; charset=UTF-8",
"date": "Thu, 23 Apr 2026 18:14:39 GMT",
"priority": "u=0,i",
"server": "cloudflare",
"server-timing": "cfExtPri",
"strict-transport-security": "max-age=15552000; includeSubdomains; preload",
"vary": "Origin,Accept-Encoding",
"x-backend": "sf-frontend",
"x-content-type-options": "nosniff",
"x-frontend-content": "PUBLISHED",
"x-request-id": "9f0a997d4e3c5309",
"x-strata-cache-tags": "homepage,blogListing,pressReleasesListing,eventsListing,newsListing,ecosystemsLandingPage,blogPosts,pages"
},
"vulnerableLibrariesAuditScore": null,
"vulnerableLibraries": []
},
"recommendations": [
{
"title": "Define a Referrer-Policy",
"urgency": "low",
"detail": "Set a referrer policy to reduce unnecessary URL data leakage."
},
{
"title": "Define a Permissions-Policy",
"urgency": "low",
"detail": "Restrict browser capabilities to only what the application needs."
}
]
},
"expectedFiles": {
"score": 45,
"urgency": "medium",
"origin": "https://www.w3.org",
"checks": [
{
"path": "/robots.txt",
"kind": "expected",
"url": "https://www.w3.org/robots.txt",
"found": true,
"status": 200,
"contentType": "text/plain"
},
{
"path": "/sitemap.xml",
"kind": "beneficial",
"url": "https://www.w3.org/sitemap.xml",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 20,
"urgency": "low",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 6,
"imagesWithLazy": 3,
"imagesWithoutLazy": 3
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
}
]
},
"wsgCustom": {
"score": 85,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": true,
"media": {
"totalImages": 6,
"lazyImages": 3,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", Geneva, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 3/6 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 14,
"urgency": "low",
"totalEstimatedSavingsBytes": 25083,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "unminified-css",
"title": "Minify CSS before transfer",
"urgency": "low",
"estimatedSavingsBytes": 18954,
"detail": "Minification amplifies compression efficiency and reduces payload size."
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript before transfer",
"urgency": "low",
"estimatedSavingsBytes": 6129,
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes."
}
],
"recommendations": [
{
"title": "Minify CSS before transfer",
"urgency": "low",
"detail": "Minification amplifies compression efficiency and reduces payload size. Estimated savings: 18.51 KB."
},
{
"title": "Minify JavaScript before transfer",
"urgency": "low",
"detail": "Minify JS bundles so transport compression produces better results with fewer bytes. Estimated savings: 5.99 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
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"totalEstimatedBlockingMs": 1201,
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{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 1201,
"displayValue": "Est savings of 1,200 ms",
"urgency": "high",
"sourceAuditId": "render-blocking-resources"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 35708,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 35 KiB",
"urgency": "medium",
"sourceAuditId": "unused-css-rules"
},
{
"id": "unminified-css",
"title": "Minify CSS",
"detail": "Use minified production CSS output to reduce bytes in transit.",
"estimatedSavingsBytes": 18954,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 19 KiB",
"urgency": "low",
"sourceAuditId": "unminified-css"
},
{
"id": "unminified-javascript",
"title": "Minify JavaScript",
"detail": "Use minified production JS output to reduce payload size.",
"estimatedSavingsBytes": 6129,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 6 KiB",
"urgency": "low",
"sourceAuditId": "unminified-javascript"
}
],
"recommendations": [
{
"title": "Eliminate render-blocking resources",
"urgency": "high",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 1201 ms."
},
{
"title": "Remove unused CSS",
"urgency": "medium",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 34.87 KB."
},
{
"title": "Minify CSS",
"urgency": "low",
"detail": "Use minified production CSS output to reduce bytes in transit. Estimated byte savings: 18.51 KB."
},
{
"title": "Minify JavaScript",
"urgency": "low",
"detail": "Use minified production JS output to reduce payload size. Estimated byte savings: 5.99 KB."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
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{
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},
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"id": "installable-manifest",
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{
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},
{
"id": "uses-long-cache-ttl",
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}
],
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{
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},
{
"title": "Improve web app manifest support",
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},
{
"title": "Support offline start URL behavior",
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"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
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}
]
},
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"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
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{
"title": "No obvious outdated runtime version disclosed",
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}
]
},
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},
"recommendations": [
{
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"categoryName": "Web Development",
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"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
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}
}
],
"wsg": {
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"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
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"renderBlockingMs": 1201,
"breakdown": {
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"unusedJavascriptSavings": 0,
"unusedCssSavings": 35708
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
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"urgency": "medium",
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"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
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"categoryName": "Web Development",
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"title": "Defer the loading of non-critical resources",
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}
}
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}
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"categoryName": "Web Development",
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"title": "Modularize bandwidth-heavy components",
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}
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},
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"categoryId": "3",
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"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
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},
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"issueTemplate": "## Improve Reduce unused CSS\n\n- Lighthouse audit: unused-css-rules\n- Current value: Est savings of 35 KiB\n- WSG guideline: 2 Remove unnecessary or redundant information\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information\n\n### Why this matters\nReduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. [Learn how to reduce unused CSS](https://developer.chrome.com/docs/lighthouse/performance/unused-css-rules/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
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},
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"issueTemplate": "## Improve Eliminate render-blocking resources\n\n- Lighthouse audit: render-blocking-resources\n- Current value: Est savings of 1,200 ms\n- WSG guideline: 18 Use the most efficient solution for your service\n- WSG link: https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service\n\n### Why this matters\nResources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources](https://developer.chrome.com/docs/lighthouse/performance/render-blocking-resources/).\n\n### Definition of done\n- [ ] Metric improves in Lighthouse on key templates\n- [ ] Changes documented in release notes\n- [ ] Re-scan confirms improvement"
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{
"path": "/.well-known/security.txt",
"kind": "beneficial",
"url": "https://www.w3.org/.well-known/security.txt",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/manifest.webmanifest",
"kind": "beneficial",
"url": "https://www.w3.org/manifest.webmanifest",
"found": false,
"status": 404,
"contentType": "text/html; charset=utf-8"
},
{
"path": "/favicon.ico",
"kind": "beneficial",
"url": "https://www.w3.org/favicon.ico",
"found": true,
"status": 200,
"contentType": "image/vnd.microsoft.icon"
}
],
"recommendations": [
{
"title": "Add beneficial discoverability and maintenance files",
"urgency": "medium",
"detail": "Missing beneficial file(s): /sitemap.xml, /.well-known/security.txt, /manifest.webmanifest."
}
]
},
"mediaHints": {
"score": 50,
"urgency": "medium",
"checks": {
"hasDarkMode": false,
"hasMetaColorScheme": false,
"hasDarkModeQuery": false,
"autoplayingMedia": [],
"autoplayCount": 0,
"unmutedAutoplayCount": 0,
"totalImages": 8,
"imagesWithLazy": 0,
"imagesWithoutLazy": 8
},
"recommendations": [
{
"title": "Add dark mode support",
"urgency": "medium",
"detail": "No prefers-color-scheme: dark media query or color-scheme meta tag was found. Dark mode reduces energy use on OLED screens and improves user choice."
},
{
"title": "Add loading=\"lazy\" to images",
"urgency": "medium",
"detail": "8 of 8 image(s) lack an explicit loading=\"lazy\" attribute. Lazy loading defers below-fold images and reduces initial page weight."
}
]
},
"wsgCustom": {
"score": 80,
"urgency": "medium",
"data": {
"hasPrintStyles": true,
"hasReducedMotion": false,
"media": {
"totalImages": 8,
"lazyImages": 0,
"totalIframes": 0,
"lazyIframes": 0
},
"typography": {
"primaryFont": "\"Noto Sans\", \"Trebuchet MS\", \"Helvetica Neue\", Arial, sans-serif",
"usesSystemFont": true
},
"tracking": {
"count": 0,
"scripts": []
},
"semantics": {
"hasNavigation": true,
"hasMainContent": true
}
},
"recommendations": [
{
"guideline": "12.3",
"title": "No reduced motion support",
"urgency": "low",
"detail": "Implement prefers-reduced-motion to allow users to disable animations, reducing compute and improving accessibility.",
"wsid": "12.control animation",
"assessor": "script",
"example": "@media (prefers-reduced-motion: reduce) {\n *, ::before, ::after {\n animation-duration: 0.01ms !important;\n animation-iteration-count: 1 !important;\n transition-duration: 0.01ms !important;\n scroll-behavior: auto !important;\n }\n}"
},
{
"guideline": "11.3",
"title": "Incomplete media lazy loading",
"urgency": "medium",
"detail": "Only 0/8 images use loading=\"lazy\". Global lazy loading reduces initial data transfer and energy consumption.",
"wsid": "11.lazy loading",
"assessor": "script",
"example": "\n\n"
},
{
"guideline": "2.4",
"title": "Review User Journey Efficiency",
"urgency": "investigate",
"detail": "Have a human walk through the main user journeys and verify they require the fewest steps possible. Unnecessary steps waste user time and device energy. Look for redundant confirmations, forced account creation, and non-essential interstitials.",
"wsid": "2.minimize non-essential content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#minimize-non-essential-content-interactivity-or-journeys",
"assessor": "human"
},
{
"guideline": "2.6",
"title": "Check for Engagement Traps",
"urgency": "investigate",
"detail": "Manually review the page for patterns that artificially prolong engagement: infinite scroll, autoplay carousels, sticky overlays, and notification permission prompts. These waste user attention and device energy.",
"wsid": "2.design to assist not distract",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#design-to-assist-and-not-to-distract",
"assessor": "human"
},
{
"guideline": "2.7",
"title": "Audit for Deceptive Design Patterns",
"urgency": "investigate",
"detail": "Have a human identify dark patterns: misleading consent dialogs, hidden unsubscribe links, forced continuity, and bait-and-switch flows. Deceptive patterns waste user time and undermine trust.",
"wsid": "2.avoid manipulative deceptive",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#avoid-being-manipulative-or-deceptive",
"assessor": "human"
},
{
"guideline": "2.14",
"title": "Verify Accessible Alternatives for All Media",
"urgency": "investigate",
"detail": "Manually check that every video has captions, every audio file has a transcript, every image has meaningful alt text, and every PDF has an accessible HTML alternative. Alternatives let assistive technology users avoid re-downloading heavy formats.",
"wsid": "2.offer suitable alternatives",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#offer-suitable-alternatives-for-every-format-used",
"assessor": "human"
},
{
"guideline": "2.18",
"title": "Confirm User Research Was Conducted",
"urgency": "investigate",
"detail": "Verify that genuine user research or usability testing has informed the design. Research-driven design reduces wasted iterations, removes unnecessary features, and ensures the product meets real needs efficiently.",
"wsid": "2.involve users early",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#involve-users-early-in-the-project",
"assessor": "human"
},
{
"guideline": "2.10",
"title": "Review Content Conciseness",
"urgency": "investigate",
"detail": "Use a Large Language Model (e.g. locally or via API) to evaluate page text for conciseness and clarity. Removing superfluous text reduces payload, reading time, and inference energy for search engines indexing this content.",
"wsid": "2.provide clear inclusive content",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#provide-clear-inclusive-content-with-purpose",
"assessor": "ai"
},
{
"guideline": "4.4",
"title": "Verify Error Pages and Redirects Are Configured",
"urgency": "investigate",
"detail": "Have a human check that custom 404 and 500 error pages exist and that there are no redirect chains longer than one hop. Broken links force wasted round-trips. Redirect chains multiply transfer costs.",
"wsid": "4.error pages redirection",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#setup-necessary-error-pages-and-redirection-links",
"assessor": "human"
},
{
"guideline": "4.10",
"title": "Review CDN Usage and Geographic Distribution",
"urgency": "investigate",
"detail": "Confirm that static assets are served from a CDN and that the CDN edge nodes are geographically close to the primary audience. CDN misuse—or absence—increases last-mile transfer distance and the associated energy cost of data delivery.",
"wsid": "4.content delivery networks",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#use-content-delivery-networks-cdns-appropriately",
"assessor": "human"
},
{
"guideline": "5.2",
"title": "Confirm a Sustainability Advocate Is Assigned",
"urgency": "investigate",
"detail": "Verify that someone on the team has explicit responsibility for web sustainability. Without a designated advocate, sustainability improvements tend to be deprioritized and never reach the backlog.",
"wsid": "5.assign sustainability advocate",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#assign-a-sustainability-advocate",
"assessor": "human"
},
{
"guideline": "5.8",
"title": "Check for a Public Sustainability Statement",
"urgency": "investigate",
"detail": "Look for a publicly accessible sustainability statement, disclosure page, or environmental policy. Mandatory disclosure requirements are growing globally and transparency builds user trust. The statement should include measurable targets and dates.",
"wsid": "5.support mandatory disclosures",
"wsgUrl": "https://www.w3.org/TR/web-sustainability-guidelines/#support-mandatory-disclosures-and-reporting",
"assessor": "human"
}
]
},
"gridAware": {
"detected": false,
"signals": {
"hasGridAwareAttr": false,
"gridAwareValue": null,
"hasInfoBar": false,
"scriptSignals": [],
"headerSignals": [],
"electricityMapsRequests": 0
},
"recommendations": [
{
"title": "Consider implementing grid-aware website adaptation",
"urgency": "investigate",
"detail": "Grid-aware websites serve lighter experiences when the local grid runs on carbon-intensive energy. The Green Web Foundation provides a JS library and edge-function plugins (Cloudflare Workers, Netlify Edge) to implement this with minimal code.",
"wsgUrl": "https://www.thegreenwebfoundation.org/tools/grid-aware-websites/",
"assessor": "human"
}
]
},
"compressionOpportunities": {
"wsgReference": {
"title": "Reduce data transfer with compression",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#reduce-data-transfer-with-compression"
},
"score": 72,
"urgency": "high",
"totalEstimatedSavingsBytes": 448520.1,
"checks": {
"hasEffectiveTextCompression": true
},
"opportunities": [
{
"id": "modern-image-formats",
"title": "Use modern image compression formats",
"urgency": "high",
"estimatedSavingsBytes": 448520.1,
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size."
}
],
"recommendations": [
{
"title": "Use modern image compression formats",
"urgency": "high",
"detail": "Prefer AVIF/WebP over legacy formats where possible to reduce transfer size. Estimated savings: 438.01 KB."
}
]
},
"optimizationOpportunities": {
"wsgReference": {
"title": "Use the most efficient solution for your service",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-most-efficient-solution-for-your-service"
},
"score": 100,
"urgency": "high",
"totalEstimatedSavingsBytes": 887119.1,
"totalEstimatedBlockingMs": 92,
"opportunities": [
{
"id": "modern-image-formats",
"title": "Serve images in next-gen formats",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP.",
"estimatedSavingsBytes": 448520.1,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 438 KiB",
"urgency": "high",
"sourceAuditId": "modern-image-formats"
},
{
"id": "uses-responsive-images",
"title": "Right-size images for viewport",
"detail": "Avoid sending larger images than the rendered size needs.",
"estimatedSavingsBytes": 423042,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 413 KiB",
"urgency": "high",
"sourceAuditId": "uses-responsive-images"
},
{
"id": "unused-css-rules",
"title": "Remove unused CSS",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped.",
"estimatedSavingsBytes": 15557,
"estimatedBlockingMs": 0,
"displayValue": "Est savings of 15 KiB",
"urgency": "low",
"sourceAuditId": "unused-css-rules"
},
{
"id": "render-blocking-resources",
"title": "Eliminate render-blocking resources",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering.",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 92,
"displayValue": "Est savings of 90 ms",
"urgency": "low",
"sourceAuditId": "render-blocking-resources"
}
],
"recommendations": [
{
"title": "Serve images in next-gen formats",
"urgency": "high",
"detail": "Convert high-byte images to more efficient formats such as AVIF or WebP. Estimated byte savings: 438.01 KB."
},
{
"title": "Right-size images for viewport",
"urgency": "high",
"detail": "Avoid sending larger images than the rendered size needs. Estimated byte savings: 413.13 KB."
},
{
"title": "Remove unused CSS",
"urgency": "low",
"detail": "Trim unused selectors and split CSS so only needed styles are shipped. Estimated byte savings: 15.19 KB."
},
{
"title": "Eliminate render-blocking resources",
"urgency": "low",
"detail": "Inline critical assets and defer non-critical scripts/styles for faster rendering. Estimated render unblocking: 92 ms."
}
]
},
"dependencyMaintenance": {
"wsgReference": {
"title": "Use dependencies appropriately and ensure maintenance",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-dependencies-appropriately-and-ensure-maintenance"
},
"score": 0,
"urgency": "low",
"vulnerableLibraryCount": 0,
"vulnerableLibraries": [],
"externalScriptsWithoutIntegrity": 0,
"recommendations": [
{
"title": "No dependency maintenance warnings detected",
"urgency": "low",
"detail": "No vulnerable dependency flags were found for this page in the current lightweight checks."
}
]
},
"offlineSupport": {
"wsgReference": {
"title": "Optimize caching and support offline access",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#optimize-caching-and-support-offline-access"
},
"score": 100,
"urgency": "high",
"checks": {
"hasServiceWorker": false,
"worksOffline": false,
"hasInstallableManifest": false,
"hasOfflineStartUrl": false,
"longCacheTtlScore": 0.5,
"cacheSavingsBytes": 537820.3333333335
},
"opportunities": [
{
"id": "service-worker",
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"id": "works-offline",
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"id": "installable-manifest",
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"id": "offline-start-url",
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"id": "uses-long-cache-ttl",
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 525.22 KB)."
}
],
"recommendations": [
{
"title": "Add service worker support",
"urgency": "high",
"detail": "Register a service worker to support resilient caching and offline behavior for key routes."
},
{
"title": "Ensure critical routes work offline",
"urgency": "high",
"detail": "Provide an offline fallback strategy for key pages and shell assets."
},
{
"title": "Improve web app manifest support",
"urgency": "medium",
"detail": "Complete manifest fields so clients can install and run an app-like experience."
},
{
"title": "Support offline start URL behavior",
"urgency": "medium",
"detail": "Ensure start URL and shell routing can load in disconnected conditions."
},
{
"title": "Strengthen static asset cache TTL",
"urgency": "medium",
"detail": "Improve long-lived cache headers for immutable static assets (estimated savings opportunity: 525.22 KB)."
}
]
},
"languageVersionGuidance": {
"wsgReference": {
"title": "Use the latest stable language version",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#use-the-latest-stable-language-version"
},
"score": 0,
"urgency": "low",
"observedTechnologies": [],
"outdatedTechnologies": [],
"vulnerableLibraryCount": 0,
"recommendations": [
{
"title": "No obvious outdated runtime version disclosed",
"urgency": "low",
"detail": "No clearly outdated runtime version signals were exposed in sampled HTTP headers. Verify language/runtime versions in source and CI since backend versions are not always externally visible."
}
]
},
"deadCode": {
"score": 1,
"urgency": "low",
"transferBytes": 621760,
"css": {
"unusedBytes": 15557,
"ratio": 0.025020908389089037,
"auditId": "unused-css-rules"
},
"javascript": {
"unusedBytes": 0,
"duplicatedBytes": 0,
"ratio": 0,
"auditIds": [
"unused-javascript",
"duplicated-javascript"
]
},
"html": {
"estimatedPenalty": 0,
"totalBodyElements": 0,
"maxDepth": 0,
"maxChildElements": 0,
"note": "HTML dead code cannot be measured directly from Lighthouse. This score estimates unnecessary markup from DOM size and complexity signals."
},
"recommendations": [
{
"area": "css",
"title": "Remove unused CSS selectors and component styles",
"urgency": "medium",
"estimatedSavingsBytes": 15557,
"strategy": "Trim styles that never match rendered markup and split component CSS so only used styles are shipped.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "4",
"title": "Remove unnecessary code",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-code",
"subheading": "Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred."
}
},
"nonCriticalResources": {
"score": 1,
"urgency": "low",
"transferBytes": 621760,
"estimatedDeferrableBytes": 15557,
"renderBlockingMs": 92,
"breakdown": {
"offscreenImageSavings": 0,
"unusedJavascriptSavings": 0,
"unusedCssSavings": 15557
},
"candidates": [
{
"title": "Inline critical CSS and defer remainder",
"area": "stylesheet",
"urgency": "medium",
"estimatedSavingsBytes": 15557,
"strategy": "Ship only above-the-fold CSS in initial render path and defer non-critical styles.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Eliminate render-blocking resources",
"area": "render-path",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"estimatedBlockingMs": 92,
"strategy": "Defer scripts/styles not required for first paint and preload only truly critical assets.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
{
"title": "Evaluate deferred loading for heavy image from www.w3.org",
"area": "image",
"urgency": "high",
"estimatedSavingsBytes": 488097,
"url": "https://www.w3.org/WAI/content-images/fundamentals/banner-with-blur.png",
"strategy": "Confirm this asset is required for first paint; defer or lazy-load if not critical.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "8",
"title": "Defer the loading of non-critical resources",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#defer-the-loading-of-non-critical-resources",
"subheading": "Avoid render-blocking slowdowns by asynchronously loading, deferring, or prioritizing external resources as appropriate."
}
},
"thirdPartyJs": {
"wsgReference": {
"title": "Give third parties the same priority as first parties during assessment",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#give-third-parties-the-same-priority-as-first-parties-during-assessment"
},
"score": 0,
"urgency": "low",
"providerCount": 0,
"requestCount": 0,
"transferBytes": 0,
"notGreenCount": 0,
"unknownCount": 0,
"scripts": [],
"recommendations": [
{
"title": "No major third-party JavaScript risk signals",
"urgency": "low",
"detail": "Continue periodic reviews so third-party additions are assessed with the same rigor as first-party code."
}
]
},
"redundancy": {
"score": 1,
"urgency": "low",
"transferBytes": 621760,
"estimatedRedundantBytes": 15557,
"redundancyRatio": 0.025020908389089037,
"relatedAuditIds": [
"unused-css-rules",
"unused-javascript",
"duplicated-javascript",
"dom-size",
"uses-text-compression",
"unminified-css",
"unminified-javascript"
],
"wasteByAudit": [
{
"auditId": "unused-css-rules",
"title": "Reduce unused CSS",
"savingsBytes": 15557,
"displayValue": "Est savings of 15 KiB"
}
],
"recommendations": [
{
"title": "Reduce unused css",
"urgency": "medium",
"estimatedSavingsBytes": 15557,
"auditId": "unused-css-rules",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "2",
"title": "Remove unnecessary or redundant information",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#remove-unnecessary-or-redundant-information",
"subheading": "Remove redundant characters from code to reduce the amount of data being stored and transferred to devices."
}
},
"modularization": {
"score": 32,
"urgency": "medium",
"totalTransferBytes": 621760,
"heavyRequestCount": 1,
"heavyBytes": 488097,
"heavyRatio": 0.7850247683993824,
"heavyRequests": [
{
"url": "https://www.w3.org/WAI/content-images/fundamentals/banner-with-blur.png",
"transferSize": 488097,
"resourceType": "image",
"mimeType": "image/png",
"domain": "www.w3.org"
}
],
"groupedByType": [
{
"resourceType": "image",
"count": 1,
"transferBytes": 488097
}
],
"groupedByOrigin": [
{
"domain": "www.w3.org",
"count": 1,
"transferBytes": 488097
}
],
"onDemandCandidates": [
{
"title": "Defer non-critical UI modules until after first render",
"urgency": "medium",
"estimatedSavingsBytes": 0,
"strategy": "Keep only above-the-fold resources in the initial path; hydrate or import secondary modules later.",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
{
"title": "Modularize heavy image asset from www.w3.org",
"urgency": "high",
"estimatedSavingsBytes": 488097,
"strategy": "Serve a smaller placeholder first and load this asset only when the user scrolls to or requests the component.",
"url": "https://www.w3.org/WAI/content-images/fundamentals/banner-with-blur.png",
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
}
],
"wsg": {
"categoryId": "3",
"categoryName": "Web Development",
"id": "3",
"title": "Modularize bandwidth-heavy components",
"url": "https://www.w3.org/TR/web-sustainability-guidelines/#modularize-bandwidth-heavy-components",
"subheading": "Break down large components into smaller, self-contained pieces that can be requested only when required to save bandwidth."
}
},
"findings": [
{
"auditId": "largest-contentful-paint",
"title": "Largest Contentful Paint",
"description": "Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric](https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/)",
"score": 0.36,
"displayValue": "4.5 s",
"impact": "high",
"wsg": {
"categoryId": "3",
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