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Color Contrast Checker

Check WCAG 2.1 color contrast compliance for accessibility. Calculate contrast ratios, test AA/AAA levels for normal and large text, and get suggestions for better contrast. Runs entirely in your browser — your data never leaves your machine.

color contrast accessibility wcag a11y developer-tools

Published May 28, 2026

All interactive tools run entirely in your browser. Your data never leaves your device.

How It Works

Enter a foreground (text) color and a background color using the color pickers or hex inputs. The tool calculates the contrast ratio per the WCAG 2.1 specification, then checks compliance against AA and AAA levels for both normal and large text.

Features

  • WCAG 2.1 compliant: uses the official relative luminance and contrast ratio formulas
  • AA and AAA levels: checks normal text, large text, and UI component thresholds
  • Live preview: see your text at multiple sizes on the actual background
  • Color suggestion: when contrast is too low, suggests a foreground color that passes AA
  • Quick presets: common color pairs to test instantly
  • Swap colors: flip foreground and background with one click
  • Private: runs entirely in the browser — no data transmitted

Use Cases

  • Ensuring your website text meets WCAG accessibility standards
  • Testing brand color combinations for readability
  • Verifying contrast ratios during design reviews
  • Finding accessible alternatives when colors fail compliance