Color Contrast Checker
Pick a text colour and a background colour. See the contrast ratio and whether it passes WCAG AA and AAA for normal and large text.
WCAG contrast requirements
Level AA needs a ratio of at least 4.5:1 for normal text and 3:1 for large text (18pt, or 14pt bold). Level AAA needs 7:1 for normal text and 4.5:1 for large text. User-interface parts such as icons and input borders need 3:1.
How the ratio is calculated
The tool converts each colour to relative luminance as defined by WCAG 2, then computes (lighter + 0.05) / (darker + 0.05).
Frequently asked questions
What contrast ratio should I aim for?
At least 4.5:1 for body text (WCAG AA). Aim higher when you can; it helps everyone, especially on phones in sunlight.
What counts as large text?
Text of 18pt (24px) or larger, or 14pt (about 18.7px) bold or larger.
Does it accept short hex like #fff?
Yes. Use #RGB or #RRGGBB.
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