Pa11y

What is Pa11y?

Pa11y is an open-source command-line tool that runs automated accessibility tests against your pages using HTML_CodeSniffer or axe-core under the hood, then reports WCAG violations in a format you can wire into a CI pipeline. It's built for teams who want accessibility checks to happen automatically on every deploy instead of relying on someone remembering to run a manual audit before launch. It won't catch everything a real audit would (automated tools never do), but it catches the mechanical stuff early and consistently.

Key features

• CLI tool that can run against a single URL or a whole sitemap of pages
• Pa11y CI wrapper for running checks as part of a build pipeline, with pass/fail thresholds you can tune
• Pa11y Dashboard for teams that want a persistent, browsable history of results over time
• Supports both HTML_CodeSniffer and axe-core as the underlying testing engine
• Configurable to ignore specific rules or elements, so you're not fighting false positives on things you've already reviewed

Who it's for

A good fit for teams that already have a CI pipeline and want automated accessibility regression testing baked into it, catching things like missing alt text or bad contrast before they ship. It's not a substitute for manual testing with real assistive technology or a full audit against WCAG success criteria, it's a first line of defense that runs itself.

Pricing

Free and open-source, no paid tier.