How to Review AI-Generated Alt Text for Web Images

An AI draft describes a photograph as “a beautiful image of people.” The sentence may be grammatical, but it does not tell a reader why the photograph is on this page. To review AI-generated alt text, inspect the image in its published context, decide whether it adds information or performs an action, and edit the draft to convey that purpose. If the image is only decoration, an empty HTML alt attribute may be the right answer. A fluent description is not automatically a useful text alternative.

This is an editorial workflow for ordinary web photographs, illustrations, icons, and simple diagrams. It does not replace a check of the page markup or a specialist review of a complex graphic. The W3C Images Tutorial explains why the same image can need a different text alternative in a different context.

Decide what the image does on this page

Read the heading, caption, nearby paragraph, and any link or button containing the image. Then ask what a reader would lose if the image disappeared. Do not start by polishing the AI sentence: a captioning model may describe visible objects accurately while missing the image's function.

Informative or decorative?

An informative photograph may show a step, a distinguishing feature, or an example the surrounding text has not already supplied. Give that missing information briefly. If the photo merely sets a mood and the page still makes complete sense without it, mark it as decorative in the publishing system. For an HTML img, that usually means alt="", not an omitted attribute. The W3C guidance on decorative images explains that redundant descriptions can add noise, and that the author must judge the image's role in context.

A photo of a notebook beside an article about writing might be decorative. The same photo in a guide comparing notebook layouts could be informative: the arrangement of the page becomes the point. Never classify a picture solely from its file name or stock-photo tags.

Functional images need a destination or action

When the image is the only content of a link or button, describe what activation does. “Magnifying glass” does less work than “Search the site.” “Company logo” may be less useful than “Company home” for a linked logo. Check the accessible name of the complete control; nearby visible text may already supply it. The W3C functional-images examples focus on the action or destination rather than the icon's appearance.

Compare the AI draft with the image and source

Open the actual image at the size and crop used on the page. List only details that matter to its purpose: the object, action, relationship, or visible label. Verify names, locations, identities, and numbers against a reliable source; do not infer them from appearance. An AI sentence such as “the team celebrates a successful launch” claims an event and emotion that a photo of people at a table cannot establish.

Use a small review table for a batch: image URL, page context, purpose, draft alt, verified visible detail, revised alt, and reviewer. If the picture contains essential words, check them against the image. The W3C images-of-text guide recommends real text where possible and equivalent words when an image of text must be used. The Google technical-writing guide to alt text also asks writers to describe an image's purpose in context and avoid repeating nearby text.

Worked example: one page, three different decisions

Imagine a fictional community-workshop page. Its text already says that registration opens on Monday. It contains a mood-setting photo of a sunlit desk, a photograph showing the room entrance beside directions, and an icon-only button linking to the registration form. These are invented editorial examples, not observations from a real event.

The AI proposes “A sunny desk with books and coffee” for the first photo. The words may be visually plausible, but the photo adds no information to the workshop details. Set the decorative image's HTML alternative to alt="" after confirming it is not also a link. The second proposal says “A building with a door.” If the image is used to identify the entrance, inspect it and write the distinctive, verified cue the directions need, such as “Workshop entrance through the blue door beside the reception desk.” Do not add a color or desk that the photo does not show. The third proposal says “Arrow icon.” If the control opens registration, its accessible name should communicate “Open workshop registration,” whether that name comes from the image alternative or another correct control label.

This pass differs from the screen reader navigation review for AI-written pages, which concentrates on headings, links, lists, and reading order. It also differs from checking a chart description against its data, where the source values and a longer explanation may be necessary.

Keep short alt text short, and move detail elsewhere

A complex diagram often cannot be explained in one alt attribute. Give it a brief identifying alternative, then place the essential relationships in adjacent text or a linked full description. The W3C complex-images tutorial describes several ways to provide the longer equivalent. Do not squeeze every label into a single run-on sentence simply because an AI tool produced one.

Avoid “image of” when it adds nothing, keyword strings written for search engines, and invented interpretations of a person's identity or feelings. Concision is useful only after you have captured the relevant meaning. The WebAIM alternative-text guide emphasizes context and shows why a technically accurate object label can still fail to serve the page.

Check the rendered page before approval

Inspect the published or previewed HTML, not only the CMS field. Confirm that every informative image has an appropriate text alternative, decorative images use an empty alternative, and icon-only controls have an understandable accessible name. Read the image alternatives in page order with surrounding text; repetition becomes easier to hear. If a responsive crop removes a detail named in the alt text, revise either the crop or the words.

Record uncertain claims for the content owner instead of asking AI to guess. The W3C alt decision tree is a useful final prompt, but a human still has to decide what the image contributes to this particular page.

FAQs

Should every image have descriptive alt text?

No. An informative image needs an equivalent for its purpose, while a purely decorative HTML image can use an empty alt attribute. An image-only control needs a meaningful name for its action or destination.

Can I approve AI alt text without seeing the image?

No. Compare the draft with the displayed image, the surrounding content, and any source needed to support specific claims. A plausible sentence can describe the wrong crop or invent a detail.

What if the image contains a complex diagram?

Use a short alternative to identify it and provide the essential detail nearby or through an accessible longer description. Check that the text conveys the relationships the diagram was included to explain.