Contrast checker

Check whether a text and background color pair meets WCAG AA/AAA contrast levels.

Hex (#336699 or #369), rgb(51,102,153), or hsl(210,50%,40%)

Everything is calculated in this browser.

WCAG 2.x luminance formula. This checks color contrast only — it does not judge readability, fonts, or other accessibility factors.

How to use

  1. Enter the text color and the background color.
  2. Run the check.
  3. Read the ratio and the AA/AAA verdicts.

What it supports

Uses the WCAG 2.x luminance formula and accepts hex, rgb(), and hsl() colors. Large-text levels apply to roughly 18 pt / 24 px (or 14 pt bold) and above. This measures color contrast only — it does not cover readability, fonts, or other accessibility requirements.

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