Free tool · no signup · runs now
Image alt attribute checker
Alt text is how image search knows what a picture shows and how screen readers describe it. Missing alt is invisible until it costs traffic.
Part of the Technical SEO audit & onpage SEO audit group — also included in the free full scan.
Checks this exact page only — it does not crawl the rest of your domain.
One free scan · anonymous preview · sign in to save the full report
2 of 18 images miss an alt attributeStatic example for Image alt attribute checker; run the check above for your own result.What it checks
See which images say nothing to image search or screen readers.
Image count, missing-alt count, first missing sample.
Reads the no-JS response only, never runs JS. One fetch shared with the full scan.
What good looks like
Good looks like every content image carrying descriptive alt, with decorative ones marked alt="". A page with zero images is na; a non-HTML response is na.
How to fix it
Add descriptive alt text to every content image; mark decorative images with alt="".
What the full scan adds
- All 34 checks in one pass — one URL, every category, a single report.
- Evidence on every row: the values found, why it fails, the fix, and a deep link per check.
- Your score against the global distribution — see where you stand.
- Sign in and the report is kept for 1 year; anonymous reports expire after 7 days.
Official source: MDN, img alt · Rule: image-alt v1 · checker library
Tracking a Google update? Run the update impact check or read the search update radar.
Frequently asked questions
Is the Image alt attribute checker free?
Yes — one free run without an account, with an anonymous preview. Sign in to save the full report and keep the evidence.
How often should I run it?
After every deploy that touches routing, templates or the checked file — and after each Google core update, to confirm nothing regressed.
Does the check run JavaScript?
No — it reads the no-JS response only, exactly what a crawler or AI agent sees when it fetches the URL.
How is this different from a full audit?
This page runs one check with its full criteria and fix notes. The free full scan runs every category at once and keeps the evidence per URL — use it once you know which checks matter.
What is an alt text checker?
An alt text checker counts the images on a page that have no alt attribute and shows the first missing ones. Alt text is the description screen readers announce and image search reads; a missing attribute leaves both with nothing.
Does every image need alt text?
Every content image should have a short description. Decorative images should carry an empty alt attribute, alt="", so screen readers skip them. The checker reports missing attributes; it cannot judge whether existing text is descriptive.