vital-scans open quality ledger

www.cdc.gov: Web standards & metadata — week 2026-W35

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%0/855
hreflang alternates declared0%0/855
Open social presence (Mastodon/Bluesky) linked0%0/855
Open Graph tags (6/6)56%481/855
Twitter card metadata56%482/855
Meta description present68%579/855
Canonical URL declared69%589/855
Character encoding declared71%611/855
Responsive viewport (zoom not disabled)71%611/855
Document language (lang) set78%670/855
Page has a <title>100%855/855

across 855 page(s)

No Mastodon/Bluesky links detected on checked pages.

Progressive Web Resilience across 855 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 ✗ 0/855 pages A service worker is what makes offline access, caching, and background sync possible. —
Manifest declares a maskable icon ✗ 0/855 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) ✗ 0/855 pages An active service worker (not just registered) is what actually intercepts requests and serves cached content. —
Service worker controls this page load ✗ 0/855 pages A controlling service worker means THIS page load is being served/intercepted, not just a future one. —
Meets basic installability criteria ✗ 0/855 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 ~ 603/855 pages A web app manifest is required for installability and controls how the app appears when launched. —
Theme color declared ~ 604/855 pages Theme color controls the browser chrome/status-bar color when the site is installed or bookmarked. #0056b3
Apple touch icon (iOS/bookmark icon) ~ 603/855 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 ~ 603/855 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) ✓ 855/855 pages HTTPS is required for service workers and most install prompts. —