What it means
An <img> element has no alt attribute at all. This is different from alt="", which is a deliberate statement that the image is decorative and should be skipped. Missing means unstated; empty means intentionally silent.
Why it matters
With no alt attribute, screen readers fall back to announcing the file name — so a user hears “i-m-g underscore four-two-nine-one dot j-p-g” where you intended a product photo. If that image is a link or a button, the consequence is worse: the control has no accessible name, and the user has no way to know what activating it will do. WCAG 2.1 criterion 1.1.1 covers this directly.
Alt text is also what search engines read to understand image content, so the same omission removes your images from image search and weakens the page’s topical signals.
How W3Audit detects it
Every image in the delivered HTML is checked for the presence of an alt attribute, and separately assessed for whether the text is useful. The automated pass finds absent attributes; the manual review catches the ones automation cannot — alt text that repeats the file name, describes the wrong thing, or says “image”. Images that are also links or buttons are reported first, because those are functional failures rather than descriptive ones.
How severe it is
High for content images. Critical when the image carries information available nowhere else, or when it acts as a link or button in a navigation or checkout flow, since the task cannot be completed. Decorative images missing an empty alt attribute are medium: noisy for screen-reader users, but not blocking.
How to fix it
Describe the function of the image in its context, as briefly as that takes. If the image is decorative, say so with an empty attribute — never omit it.
<!-- decorative: intentionally silent --> <img src="divider.svg" alt="" /> <!-- informative: describe what it conveys --> <img src="score-ring.png" alt="Site health score of 68 out of 100" /> <!-- functional: describe the destination, not the picture --> <a href="/report/"><img src="pdf.svg" alt="Download the sample audit report" /></a>
Skip “image of” and “photo of” — the screen reader already announces that it is an image. Where an image contains text, the alt text should contain the same words.
How to verify the fix
Re-run an automated check to confirm no image is missing the attribute, then read the page with a screen reader or an accessibility inspector and listen to the image announcements in order. Ask one question of each: if the image failed to load, would the remaining text still make sense? If yes, the alt text is doing its job.
Where this sits in your audit
This finding belongs to the UX & accessibility category — see the UX & accessibility audit for everything else reviewed alongside it, or the methodology for how its severity and score contribution are calculated. The website audit checklist includes it as a step you can run yourself.