Convert colors between HEX, RGB and HSL with a live swatch and a color picker
Color Contrast Checker
Runs locally
Use Color Contrast Checker
What it does
Check whether text in one color is readable on another: the tool computes the WCAG 2 contrast ratio, previews the pair and tests it against the AA and AAA limits for normal text.
It runs entirely in your browser: nothing you enter is uploaded.
Example
Mid gray on the dark default
#808080CONTRAST RATIO
4.87:1
WCAG AA (4.5:1)
✓ Pass
WCAG AAA (7:1)
✗ FailAgainst the default background #0a0f14 the ratio is 4.87:1, so AA passes and AAA fails.
FAQ
Which WCAG thresholds does it check?
Only the limits for normal text: 4.5:1 for AA and 7:1 for AAA (success criteria 1.4.3 and 1.4.6). Large text (18 pt, or 14 pt bold) needs 3:1 for AA and 4.5:1 for AAA, and user interface components need 3:1, so read those off the ratio yourself.
Which color formats can I enter?
Six-digit hex with a leading # (#1a2b3c), or use the color pickers. Three-digit hex and color names give NaN, a six-digit value without # gives a wrong ratio, and transparency is not supported.
Is anything sent to a server?
No. The ratio is calculated in your browser from the two values, and nothing is uploaded.