Best Free Accessibility Checkers in 2026: Tools Compared

Automated accessibility checkers are the fastest way to identify common WCAG violations on your website. Here is an honest comparison of the best free options available in 2026.

Quick Comparison

OnePageAudit

What it is: A web-based accessibility scanner at onepageaudit.com that checks your page against WCAG 2.2 AA criteria. Strengths:

• No installation needed. Enter a URL and get results.
• Fix instructions are written in plain language, not just WCAG criterion numbers
• Maps each violation to the specific WCAG rule
• Free scan includes compliance score and top violations
• Full report ($19) includes every violation with exact HTML elements and fix steps

Limitations:

• Free tier shows top 3 violations (full report is paid)
• Scans one page at a time (like most free tools)
• Automated only (cannot catch issues requiring human judgment)

Best for: Business owners, marketers, and non-technical team members who need to understand what is wrong and how to fix it without reading WCAG specifications.

WAVE (Web Accessibility Evaluation Tool)

What it is: A free tool from WebAIM (Utah State University's accessibility organization). Available as a web service at wave.webaim.org and as browser extensions for Chrome and Firefox. Strengths:

• Established and well-respected (WebAIM has published accessibility research for over 20 years)
• Inline error highlighting shows exactly where issues are on the page
• Categorizes results into errors, alerts, features, structural elements, and ARIA
• Contrast checker built in
• Completely free with no paid tier for the tool itself

Limitations:

• Browser extension needed for full functionality (the web service has limitations with JavaScript-heavy sites)
• Results are technical; you need to understand WCAG to interpret many findings
• Does not provide step-by-step fix instructions
• Can be overwhelming on pages with many issues (dozens of inline icons)

Best for: Developers and accessibility professionals who understand WCAG and want detailed inline visualization of issues.

Google Lighthouse

What it is: An automated auditing tool built into Chrome DevTools. Also available as a CLI tool and via PageSpeed Insights. Strengths:

• Built into Chrome (no installation for Chrome users)
• Runs accessibility alongside performance, SEO, and best practices audits
• Based on axe-core (Deque's accessibility testing engine)
• Free and maintained by Google

Limitations:

• Checks a limited subset of accessibility rules compared to dedicated tools. The Lighthouse accessibility audit does not cover all WCAG 2.2 AA criteria.
• The 0-100 score can be misleading. A score of 90+ does not mean your site is WCAG compliant. It means you passed the limited rules Lighthouse checks.
• Fix guidance is generic and links to web.dev documentation rather than providing page-specific instructions
• Designed for developers; not accessible to non-technical users

Best for: Developers who want a quick accessibility check as part of their overall site audit workflow.

Pa11y

What it is: An open-source command-line accessibility testing tool. Available at pa11y.org. Strengths:

• Fully free and open source
• CI/CD integration: add accessibility checks to your build pipeline
• Pa11y Dashboard for monitoring multiple URLs over time
• Supports WCAG 2.1 AA and AAA testing
• Can test against HTML CodeSniffer or axe-core rulesets
• Configurable: set thresholds, ignore specific rules, test authenticated pages

Limitations:

• Requires Node.js and command-line familiarity
• No graphical interface (Pa11y Dashboard exists but requires self-hosting)
• Results are technical and assume WCAG knowledge
• Setup and configuration take time

Best for: Development teams who want automated accessibility testing in their CI/CD pipeline.

Silktide

What it is: A browser extension that provides accessibility, SEO, and content quality checks. Free version available at silktide.com. Strengths:

• Clean visual interface with per-page scoring
• Checks accessibility, SEO, content, and mobile in one tool
• Highlights issues directly on the page
• Easy to understand for non-technical users

Limitations:

• Full functionality requires a paid subscription
• Free version has limited features compared to paid plans
• Primarily designed as a full website quality platform, not just accessibility
• Less depth on accessibility-specific rules compared to dedicated tools

Best for: Teams that want a combined accessibility + SEO + content quality tool and are willing to pay for the full version.

What No Automated Tool Can Do

All of these tools share the same fundamental limitation: automated testing catches roughly 30-50% of WCAG violations. No automated tool can evaluate:

• Whether alt text is actually meaningful and accurate
• Whether the reading order makes sense when content is linearized
• Whether custom interactive widgets are truly usable with assistive technology
• Whether focus management in single-page applications is logical
• Whether ARIA attributes are used correctly in context (not just syntactically valid)

Automated scanning is essential as a starting point. But it is not a substitute for keyboard testing, screen reader testing, and (for high-stakes sites) professional manual auditing.

Recommendation

Start with an automated scan to establish your baseline and fix the issues that tools can detect. OnePageAudit is the fastest way to get actionable results if you are not a developer. Pair it with keyboard testing (tab through your entire site) for a practical accessibility assessment.

Related reading:

• ADA Compliance Checker: How to Test Your Website
• How to Do a Website Accessibility Audit
• Why Accessibility Overlays Don't Protect You