HTML Accessibility Pre-check

How the HTML Accessibility Pre-check Works

This tool parses a page's server-returned HTML for selected patterns related to accessibility:

1. Enter a URL, the tool fetches the page HTML and analyzes the markup for accessibility issues.
2. Markup checks, it looks for selected patterns related to WCAG success criteria and labels separate best-practice findings.
3. Issue categorization, each issue is tagged with its WCAG criterion number, severity (error/warning/info), and POUR principle.
4. POUR principle breakdown, see how many issues fall under each WCAG principle for a structured view of your accessibility posture.
5. Detected patterns, it also lists markup patterns found in the response; these are not proof of conformance.

Why Web Accessibility Matters

Accessibility isn't optional, it's a legal requirement and a competitive advantage:

• Legal compliance, ADA (US), EAA (EU, from 2025), AODA (Canada), and similar laws require websites to be accessible. Lawsuits for inaccessible websites have increased 300% in recent years.
• Audience reach, 16% of the world's population lives with a disability. Inaccessible websites exclude potential customers and users.
• SEO benefits, many accessibility practices directly improve SEO: alt text, heading structure, semantic HTML, page titles, and proper link text are ranking signals.
• User experience, accessible design benefits everyone: captions help in noisy environments, keyboard navigation helps power users, clear structure helps all readers.
• AI search, AI engines parse semantic HTML and ARIA landmarks to understand content structure. Accessible sites are more extractable for GEO.

Pair this with the Image SEO Checker, Heading Checker, and Meta Tag Checker for a broader markup review. The Color Contrast Checker calculates selected foreground/background ratios, but a rendered-page audit is still needed. Also check mobile-friendliness, many accessibility issues (small tap targets, no viewport meta) directly overlap with mobile usability problems.

The Four WCAG Principles (POUR)

WCAG organizes accessibility requirements under four principles:

• Perceivable, content must be presentable in ways users can perceive. This covers alt text for images, captions for video, sufficient color contrast, and text alternatives.
• Operable, interface must be operable by everyone. This covers keyboard navigation, skip links, page titles, sufficient time limits, and avoiding seizure-inducing content.
• Understandable, content and interface must be understandable. This covers language declarations, consistent navigation, form labels, and error handling.
• Robust, content must work with current and future technologies. This covers valid HTML, proper ARIA usage, and compatible markup.

For deeper technical SEO fixes, check your schema markup, security headers, and overall SEO.