Best Free Accessibility Testing Tools Compared
Compare the top accessibility testing tools. Detailed reviews of axe DevTools, WAVE, Lighthouse, Pa11y, Siteimprove, and inclly with pros, cons, and use case recommendations.
There's no shortage of accessibility testing tools. But which one should you use? This guide compares the most popular free and paid options to help you choose the right tool for your workflow.
Important: No Tool Catches Everything
All automated accessibility tools share the same fundamental limitation: they catch approximately 30-40% of WCAG issues. The remaining 60-70% require manual testing by humans. Claims of "full compliance" from automation alone are inconsistent with industry research.
Quick Comparison
| Feature | axe | WAVE | Lighthouse | Pa11y | Siteimprove | inclly |
|---|---|---|---|---|---|---|
| Free tier | - | |||||
| Browser extension | - | - | ||||
| CLI / CI integration | - | - | ||||
| Scheduled monitoring | - | - | - | |||
| Code fix suggestions | - | - | - | - | ||
| Framework-specific fixes | - | - | - | - | - | |
| Manual testing guidance | - | - | - | |||
| Audit trail / compliance docs | - | - | - | |||
| Site-wide crawling | - | - | - |
Detailed Tool Reviews
axe DevTools
Browser Extension
Pros
- Zero false positives guarantee
- Excellent issue explanations
- Integrates with dev tools
- Powers many other tools (Lighthouse, etc.)
Cons
- -Only tests visible page state
- -Pro version needed for guided testing
- -No scheduling or monitoring
Developers debugging accessibility issues during development
WAVE
Browser Extension / Web Service
Pros
- Visual overlay shows issues in context
- Easy to understand icons
- Shows page structure visualization
- Good for beginners
Cons
- -Can be visually overwhelming on complex pages
- -Some false positives
- -Manual testing only (no CI/CD)
Content editors and non-technical users checking pages
Google Lighthouse
Browser Built-in / CLI
Pros
- Built into Chrome DevTools
- Tests performance, SEO, accessibility together
- CI/CD friendly (CLI and Node module)
- Powered by axe-core
Cons
- -Accessibility score can be misleading (only ~30 checks)
- -Less detailed than dedicated tools
- -No visual indicators on page
Quick audits and CI/CD integration alongside performance testing
Pa11y
CLI / Dashboard
Pros
- Fully open source
- Supports HTML CodeSniffer and axe
- Easy CI/CD integration
- Pa11y Dashboard for scheduling
Cons
- -Requires technical setup
- -No browser extension
- -Less polished UI
Dev teams wanting open source CI/CD accessibility testing
Siteimprove
Cloud Platform
Pros
- Comprehensive site-wide monitoring
- Content quality and SEO included
- Good reporting and dashboards
- Compliance documentation
Cons
- -Expensive for small teams
- -Can be slow for large sites
- -Less technical detail than dev tools
Enterprise organizations needing ongoing compliance monitoring
inclly
Cloud Platform
Pros
- Framework-specific code fixes (React, Vue, etc.)
- Transparent about automated limitations (~40%)
- Legal audit trail documentation
- Flags issues needing manual review
Cons
- -New to market (in beta)
- -Smaller community
Teams wanting honest accessibility tooling with remediation guidance
Which Tool Should You Use?
Individual Developer
Debugging issues during development
Recommendation: axe DevTools + Lighthouse
Both free, integrated into browser, catch most issues
Dev Team with CI/CD
Automated testing in deployment pipeline
Recommendation: Pa11y or Lighthouse CI
Open source, easy to integrate, fail builds on issues
Content Team
Non-technical users checking content
Recommendation: WAVE
Visual feedback, easy to understand, free
SMB Needing Compliance
Small team worried about ADA lawsuits
Recommendation: inclly
Affordable, code fixes included, audit trails for legal
Enterprise Organization
Large site needing comprehensive monitoring
Recommendation: Siteimprove or inclly Enterprise
Site-wide monitoring, compliance reporting, support
Complete Testing Strategy
Thorough accessibility program
Recommendation: Combine tools
Dev: axe | CI: Pa11y | Monitoring: inclly | Manual: real users
Frequently Asked Questions
Can I rely on just one accessibility testing tool?
For automated testing, multiple tools catch slightly different issues. More importantly, no automated tool catches more than 40% of issues. You need manual testing too. For a minimum viable approach: one automated tool (axe or Lighthouse) plus keyboard and basic screen reader testing.
Are paid accessibility tools worth it?
Depends on your needs. Free tools are sufficient for detection. Paid tools add value through: saved time (better explanations, code fixes), compliance documentation, monitoring, and support. If you're spending more than a few hours per week on accessibility, paid tools often pay for themselves.
Why do different tools report different numbers of issues?
Tools use different rule sets, configurations, and counting methods. Some count each instance separately; others group by type. Some tools have stricter rules than WCAG requires. Focus on fixing issues rather than achieving a specific number. A "100 score" in Lighthouse doesn't mean your site is fully accessible.
How do overlay widgets compare to testing tools?
Overlays are fundamentally different—they're not testing tools. They inject JavaScript that attempts to fix issues at runtime. This approach has limitations: overlays don't fix underlying code issues and can interfere with assistive technologies. Regulatory guidance indicates that code-level fixes are more reliable. We recommend actual testing and fixing over runtime modifications.
Continue Learning
Explore related guides to deepen your accessibility testing knowledge.
Automated vs Manual Testing
What each approach catches and how to build an effective testing strategy.
Manual Accessibility Testing Guide
5 essential tests every developer should know, from keyboard to screen reader.
WCAG 2.2 AA Checklist
All 50 Level A and AA success criteria with testing indicators.
Accessibility Audit Trail Guide
How to document compliance efforts your legal team will actually use.
Try inclly's Honest Approach
inclly combines automated scanning with transparency about what it can and can't catch. Get framework-specific code fixes, audit trails for compliance, and clear flags for issues requiring manual testing.
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