WCAG Contrast Checker

Use WCAG Contrast Checker for its specific task

WCAG Contrast Checker is useful for checking text and background choices before accessibility review. Each sRGB channel is linearized, combined with WCAG luminance weights, and compared using lighter plus 0.05 over darker plus 0.05. Normal-size AA text requires 4.5 to 1, AAA requires 7 to 1, and large AA text requires 3 to 1. By pairing this method with a visible result, WCAG Contrast Checker exposes how it calculates WCAG contrast ratio for two HEX colors instead of hiding the task behind a generic shell.

Black on white produces the maximum contrast ratio of 21 to 1 and passes the displayed AA and AAA thresholds. Do not judge contrast from visual intuition alone because mid-tone luminance is nonlinear. The visible default provides a reproducible verification case for WCAG Contrast Checker, while its labeled controls let another value be checked without changing the underlying method.

Method limits and local processing

Contrast conformance also depends on font size, weight, state, imagery, gradients, and the actual rendered colors. WCAG Contrast Checker performs its work locally in your browser and does not send the entered text, values, credentials, or selected file to a server. Keep that stated boundary with the result because this page intentionally handles only calculates WCAG contrast ratio for two HEX colors.