About Accessibility Checker

Check HTML content for WCAG accessibility issues and violations. Part of the DevTools Surf developer suite. Browse more tools in the Web / Frontend collection.

Use Cases

• Audit HTML templates for WCAG 2.1 AA compliance before legal review
• Catch missing alt text and ARIA roles in generated markup
• Identify color contrast violations in design system components
• Verify screen-reader accessibility of custom interactive widgets

Tips

• Paste raw HTML markup including inline styles — the checker evaluates attributes like alt, role, aria-label, and color contrast
• Filter results by WCAG level (A, AA, AAA) to prioritize legally required fixes first
• Pay attention to color contrast violations — they account for the majority of WCAG AA failures on real sites

Fun Facts

• WCAG 1.0 was published in 1999 by the W3C Web Accessibility Initiative; the current standard WCAG 2.1 dates from 2018. WCAG 2.2 added nine new criteria in 2023.
• WebAIM's annual survey found that 96.3% of home pages of the top 1 million websites had detectable WCAG 2 failures as of 2023 — a figure that has barely moved in five years.
• The most common WCAG failure on the web is low color contrast text, appearing on about 83% of pages — more than missing alt text, missing form labels, or empty links combined.

FAQ

Does passing this checker mean my site is legally compliant?

No. Automated tools detect roughly 30-40% of WCAG issues. Manual testing with assistive technologies (NVDA, VoiceOver) and real users with disabilities is required for thorough compliance.

What is WCAG AA vs AAA?

AA is the target for most websites and the level referenced in US Section 508, EU EN 301 549, and UK Equality Act guidance. AAA is aspirational — achieving it fully is not required and not realistic for most sites.

Why does it flag color contrast even when I think the colors look fine?

Human perception of contrast is inconsistent, especially for users with color vision deficiencies. WCAG uses a mathematical luminance ratio (minimum 4.5:1 for normal text) which is objective and tool-checkable.