vital-scans open quality ledger

nih.gov: image inventory

Unique images encountered on scanned pages in 2026-W29, deduplicated by URL and Alt — the same image reused across pages with the same explanation is one row. Images with alternate captions are split into separate rows.

Image alt-text coverage across 3136 page(s) scanned in 2026-W29.
CategoryCountShare
Total image occurrences47102—
Unique images2381—
Has alt text4683199%
Decorative (alt="")1600%
Missing alt attribute1110%

Alt-text quality

Beyond present-vs-missing, each unique image's alt text is classified for quality. Filenames, redundant phrasing ("image of…"), and too-short or too-long values are technically present but unhelpful — the cases a human should rewrite. Decorative and "looks good" are not problems.

Alt-text quality across 2381 unique image(s).
VerdictImagesShareWhat it means
Missing alt502%No alt attribute — a screen reader may announce the filename.
Redundant / meaningless1225%Phrases like "image of…" or bare values like "photo" add nothing.
Too short30%A single character or word unlikely to convey the image's meaning.
Too long100%So long it probably belongs in a caption or a separate description.
Looks good213890%Present, plausible, no red flags (still worth a human spot-check).
Decorative582%alt="" or aria-hidden — intentionally not announced. Not a problem.

Image detail

Up to 500 unique image occurrences from 3136 page(s) scanned, most-reused first. — click a column heading to sort