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Color Contrast Checker for Accessibility: WCAG Testing Guide

Updated 2 min readBy the TabShed team

Test your colors for WCAG accessibility compliance. Ensure your text is readable for all users including those with visual impairments.

Contrast CheckerCheck text contrast against WCAG
Open Contrast Checker
On this page
  1. Why Contrast Matters Beyond Accessibility
  2. How Contrast Ratio Is Calculated
  3. WCAG Minimum Requirements
  4. Test Your Colors

Why Contrast Matters Beyond Accessibility

Good color contrast benefits everyone — not just users with visual impairments. Low-contrast text is harder to read in bright light on mobile screens, on older monitors, or when users are tired. High contrast improves reading speed and reduces eye strain for all users.

How Contrast Ratio Is Calculated

The WCAG contrast ratio formula compares the relative luminance of two colors. Luminance = 0.2126R + 0.7152G + 0.0722B (after gamma correction). The ratio ranges from 1:1 (identical colors, no contrast) to 21:1 (black on white, maximum contrast).

WCAG Minimum Requirements

  • AA Normal text: 4.5:1 (most text on most websites)
  • AA Large text: 3:1 (18pt+ or bold 14pt+)
  • AAA Normal text: 7:1 (stricter standard)
  • UI components: 3:1 minimum

Test Your Colors

  1. Open Contrast Checker.
  2. Enter your text color (foreground) and background color.
  3. See the calculated ratio and WCAG AA/AAA pass/fail results.
  4. Adjust colors until you pass the required level.

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