Pa11y vs WAVE
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 sourceFrom $0.04 per credit (one basic page scan), falling to $0.025 at 10k+
Free tierWhat drives the bill
The metric that actually scales your invoice.
Free and open source. You pay in engineering time and CI minutes.
Free for interactive use. The API is bought in credits — one credit per basic page scan, 2-3 for advanced requests — at $0.04 each up to 999, $0.03 to 9,999 and $0.025 beyond. Minimum purchase is 250 credits ($10), and new accounts get 100 free.
Free tier
Everything, self-hosted
Browser extension and single-page online checker are free.
Open source
LGPL-3.0
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Established
OSS community · since 2013
Widely used
WebAIM (Utah State University) · since 2001
Strengths
- 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.
- The in-page visual overlay teaches non-specialists what is wrong far better than a list.
- Free for everyday developer and designer use.
- WebAIM's guidance behind each rule is authoritative and clear.
Limitations
- No guided manual testing or remediation workflow.
- Testing authenticated or interactive states requires scripting actions.
- Maintenance activity has been intermittent.
- Manual, page-by-page — not a CI tool.
- Alerts require human judgement, so counts are not directly comparable between pages.
- No issue tracking or programme management.
Best for
Teams wanting free automated accessibility gates across many pages.
Designers and developers learning accessibility, and quick manual spot checks.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.