vital-scans open quality ledger

www.cdc.gov: Web standards & metadata — week 2026-W38

Web standards & metadata

Web-standards, metadata, and security checks in the spirit of ScanGov (methodology CC0), run across our scan rather than only the homepage.

Share of checked pages passing each standard (lowest first).
StandardPass ratePages
schema.org GovernmentOrganization markup0%0/876
hreflang alternates declared0%1/876
Open social presence (Mastodon/Bluesky) linked0%0/876
Open Graph tags (6/6)59%518/876
Twitter card metadata59%518/876
Meta description present69%601/876
Canonical URL declared70%613/876
Character encoding declared72%633/876
Responsive viewport (zoom not disabled)72%633/876
Document language (lang) set80%700/876
Page has a <title>100%876/876

across 876 page(s)

No Mastodon/Bluesky links detected on checked pages.

Progressive Web Resilience across 876 page(s)

Capabilities that keep the site useful under real-world conditions — unreliable connectivity, interrupted sessions, mobile install. Not a compliance score: each row is independent evidence.

Progressive Web Resilience signals (lowest pass rate first).
CapabilityResultWhy it mattersEvidence
Service worker registered ✗ 0/876 pages A service worker is what makes offline access, caching, and background sync possible. —
Manifest declares a maskable icon ✗ 0/876 pages A maskable icon lets the OS safely crop/mask the app icon on different device shapes without clipping content. No icon with purpose "maskable"
Service worker is active (not just registered) ✗ 0/876 pages An active service worker (not just registered) is what actually intercepts requests and serves cached content. —
Service worker controls this page load ✗ 0/876 pages A controlling service worker means THIS page load is being served/intercepted, not just a future one. —
Meets basic installability criteria ✗ 0/876 pages Determines whether the browser can realistically offer "Add to Home Screen" / install, based on manifest + service worker + HTTPS together. no service worker registered
Web app manifest declared ~ 627/876 pages A web app manifest is required for installability and controls how the app appears when launched. —
Theme color declared ~ 627/876 pages Theme color controls the browser chrome/status-bar color when the site is installed or bookmarked. #0056b3
Apple touch icon (iOS/bookmark icon) ~ 627/876 pages iOS uses this icon for home-screen bookmarks and "Add to Home Screen" — without it the icon falls back to a screenshot. —
Manifest fetched and parsed successfully ~ 627/876 pages A manifest that fails to parse cannot drive installability or launch behavior even if the link is present. display=standalone, start_url=unset
HTTPS (required for service workers) ✓ 876/876 pages HTTPS is required for service workers and most install prompts. —