Pa11y

Metrics as of 2026-09-22, from the GitHub or GitLab API of each repository. Refreshed monthly.

What Pa11y is

Pa11y is an automated accessibility testing tool for web pages, usable from the command line or as a Node.js library. It loads pages in Headless Chrome through Puppeteer. HTML_CodeSniffer is the default test runner, and axe can run instead of it or alongside it. Tests check the WCAG2A or WCAG2AA standard, and WCAG2AAA is available with HTML_CodeSniffer. Built-in reporters output cli, csv, html, json or tsv results. Scripted actions can click buttons, fill form fields or wait for URL changes before a test. Exit codes, a level flag and a threshold option control when a build fails. Local HTML files can also be tested.

Written from the project's README, read 2026-09-22.

Category: Accessibility testing
License: LGPL-3.0
Language: JavaScript
Changelog: Releases on GitHub

Repository metrics

Repository metrics
Stars	4,536¹
Forks	301¹
Open issues and PRs	44¹
Contributors	63¹
Commits in the last 90 days	10¹
Last commit	2026-08-28¹
Last release	10.0.0, 2026-08-28¹
Fetched	2026-09-22

¹ Fetched from the GitHub or GitLab API on 2026-09-22. Hover a value for its own date.

Status

activeLast commit within 90 days of the fetch date.

Computed from the last commit date and the archive flag on the fetch date. See the status rules.

Alternatives

Listed accessibility testing tools, same primary language first, then by GitHub stars. Each line gives one fact from the tool's documentation where it differs from Pa11y's, with its source.

Lighthouse: Rules or standards: Accessibility audits, weighted by axe user impact assessments. source: Docs: Lighthouse accessibility score
Lighthouse CI: Rules or standards: Lighthouse regression checks for accessibility, SEO, offline support and performance. source: README
equal-access: Rules or standards: Rule policies such as IBM_Accessibility (default) and WCAG_2_1. source: Docs: accessibility-checker usage
axe-core-npm: Rules or standards: axe-core rules selected by tag, such as wcag2a (CLI --tags). source: Docs: @axe-core/cli
Pa11y CI: Browsers: Chrome (executable path set in defaults.chromeLaunchConfig.executablePath). source: README
axe-core: Rules or standards: WCAG 2.0, 2.1 and 2.2 at levels A, AA and AAA; additional rules outside WCAG. source: README
Accessibility Insights for Web: Rules or standards: WCAG 2.2 Level AA success criteria (Assessment). source: Docs: Assessment
cypress-axe: Rules or standards: axe-core rules; README example filters by tag wcag2a. source: README

Comparisons

How to install

npm install -g pa11y

From README, read 2026-09-22.

Questions

Is Pa11y open source?

Yes. Pa11y is released under LGPL-3.0, an OSI-approved license, as reported by the GitHub API on 2026-09-22.

Is Pa11y maintained?

On 2026-09-22, the last commit to the default branch was on 2026-08-28, so the listed status is active. Rule: Last commit within 90 days of the fetch date.

How many GitHub stars does Pa11y have?

4,536 stars on 2026-09-22, from the GitHub API. The number is refreshed at each monthly update.

What language is Pa11y written in?

The repository's primary language, as reported by the GitHub API, is JavaScript.

How do I install Pa11y?

The README gives this command: npm install -g pa11y

Sources

GitHub REST API: repository, read 2026-09-22
GitHub REST API: commits, read 2026-09-22
GitHub REST API: latest release, read 2026-09-22
GitHub REST API: contributors, read 2026-09-22
README, read 2026-09-22