axe-core vs Pa11y
Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.
Entry price
Free and open source
Open sourceFree and open source
Open sourceWhat drives the bill
The metric that actually scales your invoice.
Free and open source. You pay in engineering time and CI minutes.
Free and open source. You pay in engineering time and CI minutes.
Free tier
Everything, self-hosted
Everything, self-hosted
Open source
MPL-2.0
LGPL-3.0
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Category standard
Deque Systems · since 2015
Established
OSS community · since 2013
Strengths
- Effectively zero false positives, which is why it became the industry default.
- Integrates into any existing test suite in a few lines.
- Free, actively maintained, and aligned with WCAG updates.
- Free, scriptable and trivially added as a CI gate.
- Tests a sitemap of URLs in one run, unlike page-by-page extensions.
- Self-hosted dashboard for tracking without a vendor.
Limitations
- Automated rules detect roughly a third of WCAG issues — the rest need human testing.
- A library, not a workflow: no dashboards, tracking or reporting.
- Only evaluates the DOM state it is given, so dynamic states need explicit test coverage.
- No guided manual testing or remediation workflow.
- Testing authenticated or interactive states requires scripting actions.
- Maintenance activity has been intermittent.
Best for
Any team that wants accessibility checks inside their existing automated tests.
Teams wanting free automated accessibility gates across many pages.
All of these integrate with: GitHub Actions.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.