Pa11y
What it is
Pa11y is a free, open-source toolkit for finding accessibility issues on web pages. Its command-line interface performs one-off checks, while Pa11y CI evaluates lists of pages for continuous integration. Pa11y Dashboard runs daily tests and graphs improvements or regressions, with Pa11y Webservice supplying JSON data to that dashboard or a custom front end. The package runs from the command line or Node.js, supports HTML_CodeSniffer by default, and can also use the axe test runner. WCAG2AA is the default standard; WCAG2A and WCAG2AAA are selectable. Reports can be produced as readable CLI output, CSV, HTML, JSON, or TSV. Configuration accepts command-line options and JSON or JavaScript files, and local HTML files can be tested using an absolute path. Pa11y provides API access, scheduled scans, site-level scanning, and CI/CD integration. Pa11y 10 requires Node.js 22.13.0 or newer on an even-numbered release.
For and against
For
- Free and open source
- Supports WCAG 2.1 checks
- Includes scheduled dashboard scans
- Offers API and CI/CD integration
- Multiple report formats
Against
- Pa11y 10 requires Node.js 22.13.0+
- Even-numbered Node.js release required
- Installation is documented for specific operating systems
- Uses LGPL-3.0 license
The verdict
Pa11y combines one-off testing, continuous integration checks, scheduled dashboards, and API data for web accessibility work. Its standards, runners, reports, and configuration options suit technical teams managing repeatable scans.
Who it suits
It suits designers and developers who need command-line, scheduled, API, or CI-based accessibility checks. Teams working on Linux, macOS, or Windows 11 can use the documented installation requirements.
Plans and prices
Pa11y open-source tools
Free and open source tools
Read 10 Oct 2026 · pa11y.org
On the record
- API access
- Yespa11y.org · read 21 Sep 2026
- CI/CD integration
- Yespa11y.org · read 21 Sep 2026
- CI testing
- Pa11y CI iterates over a list of web pages and highlights accessibility issues, with a focus on continuous integration.pa11y.org · read 10 Oct 2026
- CLI and Node.js
- The Pa11y package runs accessibility tests from the command line or Node.js.github.com · read 10 Oct 2026
- CLI testing
- The Pa11y command-line interface loads a web page and highlights accessibility issues for one-off tests.pa11y.org · read 10 Oct 2026
- Configuration
- Pa11y supports configuration through command-line options and JSON or JavaScript configuration files.github.com · read 10 Oct 2026
- Dashboard
- Pa11y Dashboard automatically tests web pages daily and graphs improvements and regressions over time.pa11y.org · read 10 Oct 2026
- License
- The Pa11y repository lists the LGPL-3.0 license.github.com · read 10 Oct 2026
- Local file testing
- Pa11y can test a local HTML file when given an absolute path.github.com · read 10 Oct 2026
- Operating systems
- The project documents installation requirements for Linux, macOS, and Windows 11.github.com · read 10 Oct 2026
- Purpose
- Pa11y publishes free, open-source tools to help designers and developers make web pages more accessible.pa11y.org · read 10 Oct 2026
- Reports
- Built-in CLI reporters include human-readable CLI output, CSV, HTML, JSON, and TSV.github.com · read 10 Oct 2026
- Runtime requirement
- Pa11y 10 requires Node.js 22.13.0 or above, using an even-numbered Node.js version.github.com · read 10 Oct 2026
- Scan scope
- sitepa11y.org · read 21 Sep 2026
- Scheduled scans
- Yespa11y.org · read 21 Sep 2026
- Standards
- The CLI offers WCAG2AA by default and also lists WCAG2A and WCAG2AAA as selectable standards.github.com · read 10 Oct 2026
- Test runners
- Pa11y supports HTML_CodeSniffer by default and also supports the axe test runner.github.com · read 10 Oct 2026
- WCAG version
- wcag 2.1pa11y.org · read 21 Sep 2026
