AbraCalc

Color Contrast Checker

Check the WCAG contrast ratio between two hex colors and see whether the pair passes AA and AAA accessibility standards.

Embed this tool on your site

How to use this tool

  1. Enter the foreground (text) color and the background color as hex codes.
  2. The tool computes the WCAG relative luminance of each color.
  3. Read the contrast ratio and Pass/Fail results for AA and AAA thresholds.

Check whether two colors meet WCAG 2.1 contrast requirements. Minimum ratio is 4.5:1 for normal text (AA) and 7:1 for the highest AAA standard.

Frequently asked questions

What is WCAG contrast ratio?
WCAG (Web Content Accessibility Guidelines) defines a contrast ratio formula. It ranges from 1:1 (no contrast) to 21:1 (black on white). Normal body text requires at least 4.5:1 for AA compliance.
What counts as large text?
Large text is 18pt (24px) or larger, or 14pt bold (roughly 19px bold). Large text only needs a 3:1 ratio for AA.

References & sources