WCAG Color Contrast Checker (AA & AAA)

Check foreground and background color contrast ratios against WCAG 2.1 AA and AAA accessibility thresholds using exact W3C relative luminance math.

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How to Use WCAG Color Contrast Checker (AA & AAA)

  1. Input your data or choose a sample preset in the interactive workspace.
  2. Click process or calculate to execute instant client-side evaluation.
  3. Copy or export the verified output result with one click.

Verify Text & UI Contrast Against WCAG 2.1 Standards

Test foreground and background HEX color pairs using the W3C relative luminance formula to verify compliance with WCAG AA Normal Text (4.5:1), Large Text & UI Components (3.0:1), and AAA Enhanced Contrast (7.0:1), plus one-click lightness nudging.

Frequently Asked Questions

What contrast ratio is required for WCAG AA compliance?

Normal body text requires at least 4.5:1, while large text (18pt / 24px or 14pt / 18.67px bold) and non-text UI components require at least 3.0:1.

How does the Auto-Nudge to 4.5:1 feature work?

It adjusts the HSL lightness of your foreground color step-by-step away from the background luminance while preserving hue and saturation until 4.5:1 is achieved.