Convert tools

Color Contrast Checker

Calculate WCAG 2 contrast for two opaque sRGB HEX colors and check AA/AAA text thresholds.

Convert in your browser · No sign-up

Normal text uses 4.5:1 for AA and 7:1 for AAA; large text uses 3:1 and 4.5:1. Alpha blending and font-size eligibility are not evaluated.

Up to 100,000 UTF-16 units per input and 1,000,000 per result. See the supported formats and examples below.

How to use

  1. Calculate WCAG 2 contrast for two opaque sRGB HEX colors and check AA/AAA text thresholds.
  2. Choose the mode or options, then run the tool.
  3. Review the result, then copy or download the TXT file.

Example

#000000 on #ffffff → 21:1

Details and limitations

Normal text uses 4.5:1 for AA and 7:1 for AAA; large text uses 3:1 and 4.5:1. Alpha blending and font-size eligibility are not evaluated.

Text stays in your browser; it is not sent to a conversion server.

FAQ

Color Contrast Checker — What are the supported inputs and limits?

Normal text uses 4.5:1 for AA and 7:1 for AAA; large text uses 3:1 and 4.5:1. Alpha blending and font-size eligibility are not evaluated.

Format references

Tool page updated: