Pa11y

Pa11y is a free, open-source set of web accessibility tools for designers and developers. It suits teams that want to check pages from the command line, monitor them on a schedule, or put testing into CI. Its breadth is useful, but the developer-oriented workflow and Node.js requirement make it a poor fit for people seeking a turnkey service.

Overview

Pa11y covers the path from a single-page check to ongoing site monitoring. Its CLI loads a page and reports accessibility issues; Pa11y CI checks a list of pages in a continuous-integration workflow; and Pa11y Dashboard runs daily tests and charts improvements and regressions. The Webservice supplies JSON data for the Dashboard or for a custom dashboard-like interface.

The tools test websites against WCAG 2.1. The CLI uses WCAG2AA by default, with WCAG2A and WCAG2AAA also selectable. That range lets a team choose a target, though automated checks are best understood as one part of accessibility work rather than a complete substitute for human evaluation.

Key features

Flexible checks and reporting

The CLI can test a live page or a local HTML file when given its absolute path. HTML_CodeSniffer is the default test runner, and axe is also supported. Human-readable terminal output and CSV, HTML, JSON, or TSV reports give teams a choice between reviewing findings directly and passing results into other workflows.

Command-line options and JSON or JavaScript configuration files support repeatable setups. Pa11y’s collection of tools is a practical advantage for teams already working in development environments: they can use a quick check, a CI run, or daily monitoring without changing products. The trade-off is that the workflow assumes technical setup and maintenance.

Runtime and deployment

Pa11y runs from the command line or Node.js, and Pa11y 10 requires Node.js 22.13.0 or later on an even-numbered Node.js version. That is a meaningful constraint for teams with older runtimes or fixed build environments. The project documents installation requirements for Linux, macOS, and Windows 11; its platforms also include API, web, and self-hosted use.

Pricing

Pa11y open-source tools: free. The tools are free and open source, with no paid tier or plan-based feature split described. That makes Pa11y a straightforward choice where a team can supply the technical setup and hosting it needs. The repository lists the LGPL-3.0 license, which organizations should review against their own use and distribution requirements.

Platforms

Pa11y supports API, Linux, macOS, self-hosted, web, and Windows platforms. It offers API access, scheduled scans, and CI/CD integration. Those options support both locally run checks and team workflows, but the documented Windows installation requirement is specifically for Windows 11.

Who it's for

Pa11y is best for developers and accessibility teams that want free tools they can integrate into a site-testing process, especially when daily trend tracking or CI checks matter. It is less suitable for users who need a managed, nontechnical service or cannot meet the Node.js requirement for Pa11y 10.

Pros and cons

• Pro: One toolkit handles one-off checks, CI runs, and daily dashboard monitoring, so teams can cover different stages of a web workflow.
• Pro: Multiple selectable standards, two test runners, and five built-in report formats give technical users useful control over checks and outputs.
• Con: Pa11y 10 requires a recent, even-numbered Node.js runtime, which can rule it out in constrained environments.
• Con: Its command-line, configuration, and self-hosted options favor technically capable teams over users seeking a ready-made service.

Alternatives

If you want a different free accessibility tool, compare Website Accessibility Tools and Accessibility Testing Software.

• WAVE is worth considering if you want a freemium option with web and extension platforms as well as an API; its subscription API starts at $10 a month with a 250-credit minimum purchase.
• Octopus Scanner (formerly A11y Scanner) is another free option for macOS and Windows, with optional support payments.
• IBM Equal Access Accessibility Checker offers free and open-source browser extensions and CI/CD and automated testing packages.
• Oobee is a free, open-source option powered by GovTech Singapore that can scan a page or a whole site.
• Axe DevTools may suit users who want an extension with a free one-page-at-a-time tier and a Pro plan with AI-enhanced features and Intelligent Guided Testing.
• Accessibility Insights for Web is a free, open-source option for Chrome and Microsoft Edge.
• axe-core is a free, open-source accessibility testing engine under the MPL-2.0 license.
• Pope Tech may suit teams that want a free tier capped at 25 pages, two users, one website, and one group.

Verdict

Choose Pa11y if your team wants free, open-source accessibility checks that can extend from a developer’s terminal into CI and daily monitoring. The main reason to choose it is that range; look elsewhere if you need a less technical service or cannot run the required Node.js version.