Instantly scan any website for WCAG AA and AAA colour contrast failures — including simulations for Protanopia, Deuteranopia, and Tritanopia colour blindness. Free, no sign-up required. Built for developers, designers, and accessibility consultants.

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Vision Mode

WCAG Level

Normal · AA

✓ Pass⚠ Warning (< threshold × 1.5)✕ Fail

Manual Colour Contrast Checker

Foreground

#FFFFFF

Background

#1A1A1A

17.40:1

AAAAAAA Large

What is WCAG Colour Contrast?

The Web Content Accessibility Guidelines (WCAG) define minimum contrast ratios between text and background colours. WCAG AA requires a 4.5:1 ratio for normal text and 3:1 for large text. WCAG AAA requires 7:1 for normal text — the gold standard for accessibility.

Why Test for Colour Blindness?

Approximately 1 in 12 men and 1 in 200 women have some form of colour vision deficiency. A11yScan simulates Protanopia (red-blind), Deuteranopia (green-blind), and Tritanopia (blue-blind) to help you ensure your UI works for everyone.

Free Accessibility Audit Tool

A11yScan scans live websites using a real browser engine, capturing accurate computed colours from rendered pages. No extensions to install, no sign-up required. Export your results as a PDF accessibility report to share with your team or clients.

Who Is This For?

Built for web developers, UI/UX designers, and accessibility consultants who need fast, reliable WCAG compliance checking. Useful for design reviews, client audits, and ensuring legal compliance with accessibility standards like AODA, ADA, and EN 301 549.