Check color contrast for WCAG accessibility compliance. Enter a foreground and background colour, see the contrast ratio and pass/fail status for AA and AAA at all three text sizes.

WCAG (Web Content Accessibility Guidelines) requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (AA). AAA bumps these to 7:1 and 4.5:1. Failing accessibility audits costs traffic, fails procurement reviews, and locks out users with low vision.

The ratio is computed from the relative luminance of each colour using the WCAG formula. Adjust either colour with the picker until the ratio passes — most violations fix in 2-3 tweaks.

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