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Image Alt Text Checker

This image alt text checker fetches a single URL and reads the alt attribute on every image it finds, so you can see which images have no alt text at all, which are marked alt="" (the correct way to flag a purely decorative image) and which already carry real, descriptive text.

Note

We fetch the URL server-side and read every <img> tag's alt attribute. alt="" is correct markup for a decorative image, not a defect, so we only flag an image whose alt attribute is absent entirely or contains only whitespace.

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What this image alt text checker shows you

Paste a URL and it is fetched server-side. The tool reads every <img> tag on the page and sorts each one into three states: no alt attribute at all, alt="" (empty, marking the image as decorative), or alt text with real content. Only the first is a genuine defect; the other two are both correct markup for different kinds of image.

Why alt="" is not a defect, even though it looks empty

An empty alt attribute is the W3C-correct way to mark an image as purely decorative, telling assistive technology to skip it because it carries no information a screen reader needs to announce. The defect is an ABSENT alt attribute, not a deliberately empty one: without it, a screen reader falls back to reading out the image's file name, which is rarely useful and sometimes confusing. A checker that flags every alt="" as an error pushes you toward writing text for images that do not need it.

The one case an empty alt does not excuse

Whitespace inside the attribute, alt=" " rather than alt="", is treated as a defect here rather than as decorative markup. Nobody marks an image decorative by typing a space; it reads as an accident, and the fix is either real descriptive text or a genuinely empty attribute.

What good alt text actually says

Alt text should describe what the image shows or does, in the context of the page, concisely enough that a screen reader user gets the same information a sighted visitor does at a glance. "Image of a chart" describes nothing useful; "Bar chart showing organic clicks rising from 400 to 1,200 over six months" does the job. It is also read by image search, so a vague or missing description forfeits that traffic on top of the accessibility cost.

One page here, your whole site there

Checking a page you already suspect is useful, but the images that quietly cost the most are usually repeated across a template: a product gallery, an author avatar, an icon set used on every post. Finding every offending image means crawling the whole site rather than testing pages one at a time. Crawl Cove catalogues every image it crawls (alt text, declared width and height, and the page it sits on) in one pass.

Image SEO checker (whole-site) · Full site audit

Frequently asked questions

What is alt text?
A text description added to an HTML <img> tag's alt attribute. Screen readers announce it in place of the image, and search engines use it to understand what the image shows, since they cannot see it themselves.
Is alt="" the same as missing alt text?
No. alt="" is a deliberate, correct way to mark an image as purely decorative, telling assistive technology to skip it. A missing alt attribute is the real defect, because a screen reader then falls back to reading out the file name instead.
Should every image have descriptive alt text?
No. Purely decorative images (a background flourish, a spacer, an icon that repeats a nearby text label) are better served by alt="" than by forced description. Meaningful images, product photos, charts, screenshots, should have real, concise alt text.
Does alt text affect SEO?
Yes, mainly through image search: search engines read alt text to understand and index an image, so a missing or vague description forfeits that traffic. It does not directly affect the ranking of the surrounding page in the way, say, a title tag does.
Is this image alt text checker free?
Yes. It is completely free and needs no sign-up. Enter a URL and every image tag on that page is fetched and read server-side.
Can I check a page I do not own?
Yes, the same as any browser could reach the URL directly. It is a read-only check: one request to the page, nothing is submitted to the target, and results are not stored anywhere you or anyone else can browse back to.
Does this check every image on my site?
No, this checks one URL you enter at a time, up to 200 images on that page. Crawl Cove catalogues every image across your whole site as it crawls, with the page each one sits on, so a template reused across many pages is flagged everywhere it appears.

From one page to your whole site

This checks one page. Crawl Cove catalogues every image on your whole site as it crawls, alt text, declared width and height, and the page each one sits on, so a gallery template used across 40 pages is flagged once per page rather than once per site. See audit image alt text across your whole site or compare the plans.

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