Review AI Alt Text by Asking What the Image Does

‘A beautiful image of people’ may be a grammatical caption, but it rarely explains what the picture contributes. AI alt text needs a different review: inspect the displayed image in its page context, decide its purpose, and convey the information or action the reader needs. Sometimes the appropriate result is an empty alternative.

This workflow concerns ordinary photographs, illustrations, icons and simple diagrams on the web. It does not replace markup checks or specialist review of a complex visual. The W3C Images Tutorial explains why an image's context can change its text alternative.

Determine the purpose before editing the sentence

Read the heading, caption, neighboring paragraph and any enclosing link or button. Ask what would be lost if the picture disappeared. A model may identify the objects accurately while missing why the author placed them here.

An informative image might supply a distinguishing feature, demonstrate a step or present an example absent from the text. Describe that contribution briefly. A mood-setting image that adds no information may be decorative. For an HTML image, that usually means an empty alt attribute, written as alt="", rather than leaving the attribute out. W3C's decorative-image guidance discusses the unnecessary noise that redundant descriptions can create.

A notebook photograph beside a general writing article might be decorative. In a comparison of page layouts, the same photograph could convey the essential example. A file name or stock-photo tag cannot make the decision for you.

For a control, name the action

If an image is the only content of a button or link, its purpose is functional. ‘Search the site’ communicates more than ‘magnifying glass.’ A linked logo may need to identify the company home destination rather than merely announce a logo.

Check the complete control's accessible name, including any visible text that already labels it. W3C's functional-image examples focus on the action or destination. Avoid adding a second label that repeats information the control already exposes correctly.

Verify what the displayed image supports

Open the version actually used on the page, including its crop and size. Identify the relevant object, action, relationship or visible label. Specific names, numbers, places and identities need reliable support; appearance alone does not establish them.

For example, people sitting at a table do not establish that ‘the team celebrates a successful launch.’ The sentence invents both the event and its interpretation. Record uncertainty for the owner instead of asking the model to guess.

For batches, keep a review record with image URL, page context, purpose, draft alternative, verified detail, revision and reviewer. If essential words appear inside the image, check them against the image itself. The W3C images-of-text tutorial favors actual text where possible and equivalent wording where an image of text is necessary. Google's alt-text writing guidance likewise emphasizes purpose and avoiding redundant surrounding text.

Three decisions on one fictional page

Imagine an invented community-workshop page whose text already says registration opens Monday. It contains a sunlit-desk photograph for atmosphere, an entrance photograph beside directions and an icon-only registration button. These are teaching examples, not observations from a real event.

For the desk photo, AI suggests ‘A sunny desk with books and coffee.’ Even if accurate, it adds nothing necessary to the event information. Confirm the image is not also a link, then mark it decorative with an empty HTML alternative.

For the entrance, ‘A building with a door’ misses the directional purpose. Inspect the image and supply the verified distinguishing cue. ‘Workshop entrance through the blue door beside the reception desk’ is suitable only if the image actually shows that door, color and desk. Do not borrow those details from the example without evidence.

For the button, ‘Arrow icon’ describes appearance rather than function. The control should expose a name such as ‘Open workshop registration,’ whether supplied by the image alternative or another correctly implemented label.

These decisions differ from a screen reader navigation review, which concentrates on headings, links and reading order. They also differ from checking a chart against its data, where underlying values and a longer explanation may be essential.

Keep brief alternatives focused

A complex diagram may require more than a short alt attribute can usefully carry. Identify it briefly, then provide its important relationships in adjacent text or an accessible linked description. The W3C complex-image tutorial describes ways to deliver that fuller equivalent. Avoid turning every label into a single run-on sentence.

Omit ‘image of’ where it contributes nothing. Avoid search-keyword lists and unsupported interpretations of identity or feeling. WebAIM's alternative-text guidance emphasizes that an accurate object label can still fail the page's purpose.

A grammar and style check can help tighten wording after the purpose is established. Then compare the edited meaning with the approved description; brevity helps only while the necessary information survives.

Inspect the published implementation

Check the preview or final HTML, not just the CMS field. Informative images need suitable alternatives, decorative images need the intended empty alternative, and image-only controls need understandable accessible names. Read the page in order with the surrounding prose to catch repetition.

Check responsive crops. If a smaller-screen version removes a detail named in the text, change the crop or description. Confirm that the W3C alt decision tree leads to a decision that fits this page, while remembering that a person still has to interpret the image's role.

Questions about AI alt text

Should all images receive descriptive text?

No. Informative images need equivalents for their purpose; decorative HTML images may use an empty alternative. An image-only control needs a name for the action or destination.

Can I approve a description without seeing the image?

No. Compare it with the displayed version, context and sources needed for specific claims. Plausible language can describe an obsolete crop or invent a detail.

How should I handle a complex diagram?

Use a short identification and supply essential detail nearby or through an accessible longer description. Check that the text preserves the relationships the diagram was included to communicate.