HTML Accessibility Checker | WCAG & ADA Compliance Validator

HTML accessibility checker that scans pasted markup for WCAG 2.2 failures: missing alt text, unlabeled form fields, skipped headings, and broken ARIA. Free, no signup.

Also known as: html accessibility checker · wcag compliance checker · accessibility validator online · check html for accessibility · ada compliance checker · section 508 checker · aria validator

html tools

text tools

validators

HTML Input

Accessibility Report

About HTML Accessibility Checker

Scan pasted HTML for the WCAG failures that are visible in the markup itself, with the element, the success criterion, and the fix for each one.

Key Features

Runs 30 rules covering missing alt text, unlabeled form fields, empty links and buttons, skipped heading levels, duplicate ids, untitled iframes and blocked pinch-zoom
Validates ARIA properly: unknown roles, misspelled aria-* attributes, aria-labelledby pointing at an id that does not exist, and aria-hidden wrapped around something focusable
Names the WCAG 2.2 success criterion behind every finding, so a report can go straight into a VPAT, an accessibility audit, or a ticket

Use Cases

Check a component's markup for ADA and Section 508 problems before it ships, without installing a browser extension
Audit HTML emailed over by a contractor or produced by a page builder you do not control
Settle an accessibility ticket by pasting the rendered element from DevTools and reading the exact criterion it fails

Related Keywords

html accessibility checker

wcag compliance checker

accessibility validator online

check html for accessibility

ada compliance checker

section 508 checker

aria validator

web accessibility testing tool

What static analysis can and cannot catch

Roughly a third of WCAG failures are visible in the markup, and those are what this tool finds. The rest need a rendered page or a human: color contrast depends on computed CSS, focus visibility and keyboard order depend on live interaction, and whether alt text is actually a good description is a judgment call no tool can make. A clean report here means the structural failures are gone, not that the page is accessible. Test with a keyboard and a screen reader before you claim conformance.

Parsed in your browser, never uploaded

The page is parsed with the browser's own DOMParser and never leaves your machine, so internal admin screens and unreleased markup are safe to paste.

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Frequently asked questions

What is HTML Accessibility Checker used for?

HTML accessibility checker that scans pasted markup for WCAG 2.2 failures: missing alt text, unlabeled form fields, skipped headings, and broken ARIA. Free, no signup.

Is HTML Accessibility Checker free to use?

Yes. HTML Accessibility Checker is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use HTML Accessibility Checker?

No. HTML Accessibility Checker works immediately in your browser with no signup, login, or email address required.

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