Alt Text Audit: How to Review the Alt Text You Already Have
Most alt text advice targets the empty field: the image with no description at all. That is the easy case. The harder case is the site where every image has something in the alt field — a file name, a keyword, a copy-pasted phrase — and nobody has looked at any of it in years.
An alt text audit is a review of the descriptions you already have. It catches the placeholder text that satisfies a scanner while helping no one, the redundant openers that waste a screen reader user's time, and the descriptions that were accurate when the page was written but no longer match what the page sells.
The four failure modes a missing-alt-text check will never catch
These all pass a “does an alt attribute exist?” test. They fail the actual job of alt text: telling someone who cannot see the image what they need to know.
| Failure mode | What it looks like | Why it fails |
|---|---|---|
| File name as description | IMG_2041.jpg, hero-final-2.png | Describes the file, not the image; reads as noise. |
| Redundant opener | “Image of a woman at a desk” | Screen readers already announce “image”; the phrase adds nothing. |
| Keyword stuffing | “best running shoes buy running shoes running shoes sale” | Unreadable as a sentence and a known spam signal. |
| Copy-paste duplicate | Twenty product photos with the same store name | Says nothing about the specific image; wastes the slot. |
There is a fifth, subtler problem: descriptions that are grammatically fine but say the wrong thing. A “screenshot of the dashboard” that shows a specific report, a team photo whose caption names the people, an infographic whose alt repeats the title but not the finding. Context is the whole point.
What a good alt text needs
- Specific to this image. If the description could sit on another photo in your library, it is not doing its job.
- The context the page needs. An image used in a tutorial needs the step it illustrates; a product photo needs the visible material or variation, not the product title again.
- Short, with nothing redundant. One or two sentences is usually enough. Skip “image of”, “picture of”, and the page title the reader has already heard.
- Empty when the image is decorative. A divider, a background texture, or a stock photo with no information should use
alt="", not a description.
If you need concrete phrasing, the examples guide has twenty good and bad descriptions side by side.
A 15-minute manual audit
You do not need to read every description on the site. Sample the images that carry traffic and revenue, then fix the pattern those samples reveal.
- Pick 20 images. The homepage, three top blog posts, and the product or service pages that get the most visits.
- Open the media library and search for the file names you see on those pages.
- Score each alt text from 0 to 2. 2 = specific and useful; 1 = exists but generic; 0 = missing, a file name, or actively wrong. Use the criteria above, not your memory of what the image is supposed to say.
- Write down the pattern. If more than a third of the sample scores 1 or 0, the site has an audit problem, not twenty small mistakes.
| Alt text | Score | Reason |
|---|---|---|
IMG_8802.jpg | 0 | File name serves only the person who took the photo. |
| “Image of a shoe” | 1 | Exists and is true, but adds nothing to the product page. |
| “Black leather sneaker with a tan gum sole, side view” | 2 | Specific, product-visible detail, no filler. |
alt="" on a decorative divider | 2 | Correctly marked as decoration for assistive technology. |
What to do with the results
Fix in order of impact, not alphabetically. Images on high-traffic pages come first, then repeated template images (headers, author avatars, category badges), then product galleries, and finally media that no page uses. Unused files are a storage problem, not an accessibility one; do not spend the first day there.
For small sites, editing the worst twenty by hand is often enough. For a library with hundreds of images, the same review-first workflow you would use for missing alt text works here: generate a fresh suggestion, compare it with the current text, keep the better one, save in batches.
Auditing and improving at scale
AltMint’s free plugin has two scan modes. The default lists only images with missing alt text, so a routine scan cannot touch descriptions you already wrote. The All images mode lists everything, including images with existing alt text, and shows the current description beside each suggestion.
That makes the audit concrete: scan All images, sort your attention to the weak entries, generate a suggestion only where you want one, and save nothing until you have compared the two versions. Suggestions are stored separately from the published alt attribute, so a midpoint between “audit” and “fix” is allowed. The bulk editing guide covers the batch mechanics; the missing-alt guide covers the other scan direction.
Before and after: four rewrites
| Before | After | What changed |
|---|---|---|
| hero-3.jpg | “Warehouse team packing orders at a standing desk” | Replaced a file name with a scene. |
| “Image of the pricing page” | “Pricing page comparing the Free, Starter and Growth plans” | Dropped the opener, added the useful detail. |
| “shoes, sneakers, footwear, sale” | “Navy canvas sneaker with a white rubber sole” | Replaced keywords with visible attributes. |
| “Screenshot” on all six docs | “Settings screen showing the API key field” | Made each description specific to its step. |
When to leave well enough alone
An audit is not a licence to rewrite everything. If a description is specific, accurate, and short, leave it. If the image is decorative, the right change is often deleting the alt text, not replacing it. And if the same informative image appears twice on a page, one of the two can usually be marked decorative — the reader does not need the same sentence twice.
Frequently asked questions
How do I tell whether existing alt text is bad?
Read it aloud without looking at the image. If you cannot picture the image, or you learn nothing you did not already know from the page, it is weak. File names, “image of”, keyword lists, and duplicated store names are the reliable tells.
Should I rewrite every alt text on the site?
No. Sample first, then fix the images that carry traffic and the patterns the sample exposes. Rewriting accurate descriptions adds work and risk without improving anything.
Does changing alt text hurt SEO?
Replacing a bad description with a specific one is usually neutral-to-positive. The risk comes from bulk-overwriting good alt text with generic filler, which is why review-before-save matters more than speed.
How often should I audit?
Once a year for a stable site, and after a redesign, migration, or a new product line. A lightweight spot check every quarter catches template changes before they spread across the library.