Alt Text Strategy: Writing Image Descriptions That Hold Up

Alt text is a writing problem, not a coding problem

Missing alt text is one of the easiest findings for any scanner to detect, which is why it shows up in almost every audit report.

The code fix takes seconds. The hard part is deciding what each image should say. That is a writing decision, and most teams have never been given a framework for it.

WCAG Success Criterion 1.1.1 asks for a text alternative that serves the equivalent purpose of the image. Equivalent purpose is the key phrase. The question is never what does this image show. The question is what job does this image do on this page.

Start by sorting images into four jobs

Almost every image on a business website does one of four jobs.

Some images carry information. A product photo, a chart, a map, a photo of the storefront. If the image disappeared, the page would say less.

Some images are functional. A logo that links home, an icon that submits a search, a thumbnail that opens a gallery. The image acts as a control.

Some images are decorative. A texture, a divider, a generic stock photo that sets a mood. If the image disappeared, the page would say exactly the same thing.

Some images contain text. A banner with the phone number baked into the pixels, a menu uploaded as a photo, a promotional graphic with the offer inside the image.

Each job gets a different treatment, and mixing them up is where most alt text goes wrong.

Informative images: describe the purpose, not the pixels

For a product photo, the useful alt text is the product and the details a buyer would want. Brown leather work boot with steel toe, side view. Not image of shoe. Not a paragraph about the lighting.

For a chart, summarize the takeaway the chart was included to make. Monthly revenue rising from January through June. If the data matters in detail, the numbers belong in the page as a table, not in the alt attribute.

For photos of people and places, name what matters in context. The team standing outside the new Pasadena office says more than three people smiling.

Length guidance is simple. One sentence is usually right. If the description needs more than two sentences, the content probably belongs in the page itself.

Functional images: name the action

When an image is a control, the alt text should say what the control does, not what the picture looks like.

A magnifying glass icon that submits a search should be named Search. Not magnifying glass. A logo that links to the homepage should be named with the business name. Not logo.

This is the rule that fixes icon buttons across a site. The visitor hears the action, presses it, and gets the result they expected.

Decorative images: empty alt is the correct answer

Decorative images should carry an empty alt attribute. That is alt with nothing inside it, which tells a screen reader to skip the image entirely.

This is not a shortcut or a cheat. Announcing decorative swirl divider graphic forty times down a page is noise that makes the real content harder to reach.

The common mistake is the opposite of missing alt text. It is filler alt text. Words like image, photo, graphic, or banner add nothing and cost attention. If the honest description adds no information, the image is decorative and the alt should be empty.

Images of text: move the text out of the image

Text baked into an image is invisible to screen readers, search engines, and anyone who zooms or translates the page.

The durable fix is to rebuild the content as real text styled with CSS. WCAG Success Criterion 1.4.5 points in exactly this direction. Where the image of text genuinely cannot be replaced, the alt text must carry the full text, including the phone number or the offer.

Restaurant menus uploaded as photos are the classic case. The menu is often the single most important content on the site, and as an image it is unreadable to a meaningful slice of visitors.

What scanners can and cannot tell you about alt text

An automated scan reliably finds images with no alt attribute at all. That is real signal, and it is worth fixing every one.

What a scanner cannot judge is quality. It cannot tell that alt text reading IMG_2034 came from a camera filename, that a product photo is described as image, or that a decorative background is narrating itself on every page. Those calls need a human pass.

This is also where keyword stuffing gets caught. Alt text packed with search phrases reads as spam to the person listening to it, and it does not serve the equivalent purpose rule. Write for the visitor first.

A maintenance habit, not a one-time cleanup

Alt text decays. New products get uploaded, new blog images get dropped in, and the discipline slips unless it lives in the workflow.

The fix is to put the alt decision at the moment of upload. Most content systems prompt for it. The four job sort takes seconds once the team knows it.

A free scan shows you in about a minute whether the pages you care about are shipping images with no text alternative at all. The full audit report lists each image finding with a screenshot and its WCAG reference, so the cleanup pass has a concrete worklist instead of a vague goal.

No automated check can certify compliance, and good alt text alone does not make a site accessible. It is one pattern among several. It is also one of the cheapest to fix well, and the work supports remediation toward WCAG 2.1 and 2.2 AA. Our compliance guide shows where image fixes sit in the larger picture.