Image alt text
Alt text is an accessibility feature before it is an SEO feature. That ordering decides what SnippetGrove writes and what it refuses to.
What good alt text is
Alt text is read aloud, by a screen reader, to somebody who cannot see the image. So SnippetGrove writes a short phrase describing what is in the picture and what matters about it here — and specifically does not write:
- Anything beginning "Image of…" or "Photo of…". The screen reader has already announced that it is an image. Prefixing it makes every image read "image, image of a kettle".
- Keywords. A stuffed alt attribute is worse for the person it exists for than the blank it replaced, and search engines stopped rewarding it a long time ago.
- Anything longer than about 125 characters. Beyond that assistive technology truncates it, or reads a paragraph where a phrase was wanted.
Images that are left alone
Some images should have empty alt text, and getting this wrong makes a site less accessible rather than more: a caption on a spacer is read out loud where the blank would have been skipped entirely.
SnippetGrove skips an image when:
- it is smaller than 100×100 pixels on either axis — adjustable in Settings; or
-
its filename looks decorative —
spacer,divider,bg-,icon-and similar, also adjustable; or - it already has alt text, which is never overwritten.
An image with no size information — an SVG, or one whose metadata never generated — is treated as a candidate rather than skipped. A missing number is not evidence of decoration.
Where alt text is stored
In WordPress itself, independently of your SEO plugin. Alt text works with Yoast, Rank Math, All in One SEO, SEOPress or no SEO plugin. On sites without an SEO plugin, SnippetGrove also provides native metadata tags.
It also means alt text you already wrote in the media library is visible to SnippetGrove as existing coverage, and is never touched.
Alt text is never replaced in bulk
Unlike titles and descriptions, there is no "replace what is already written" option for images. Replacing a caption somebody wrote for a screen-reader user, across a whole library, is a worse thing to get wrong — so it is not offered.