Contrast ratio

The lightness difference between text and its background, as a ratio from 1:1 to 21:1.

By Mackenzie Bowes · mackenzie@mackenziebowes.com · @_mackenziebowes on X

Source

“of at least 4.5:1, except for the following” Understanding SC 1.4.3: Contrast (Minimum) (W3C)

See also: WCAG, Conformance level, Target size.