contrast ratio
The luminance ratio between text and its background, which WCAG requires to be at least 4.5 to 1 for normal text and 3 to 1 for large text.
What contrast ratio does not show
It must hold in hover and focus states as well as at rest, which is where most passing pages fail; a check that reads only the resting colours misses it.
Where contrast ratio comes up on this site
- How to test text color contrast on hover and keyboard focusWhat contrast ratio does WCAG 2.1 require?
Related terms in Accessibility and provenance
What a page owes a keyboard, a screen reader and a fact-checker: the accessibility basics and the C2PA vocabulary for proving where a file came from.
Keyboard accessibility · Focus order · Focus indicator · ARIA · Accessible description · Color contrast · Reduced motion · Captions · Audio description · Status message · Content Credential · C2PA assertion · C2PA claim · Claim signature · Manifest store · Content binding · Hard binding · Soft binding · Ingredient · Trust list · landmark
Questions about contrast ratio
What is contrast ratio?
The luminance ratio between text and its background, which WCAG requires to be at least 4.5 to 1 for normal text and 3 to 1 for large text.
What does contrast ratio not show or guarantee?
It must hold in hover and focus states as well as at rest, which is where most passing pages fail; a check that reads only the resting colours misses it.
Which area of the glossary does contrast ratio belong to?
Accessibility and provenance: What a page owes a keyboard, a screen reader and a fact-checker: the accessibility basics and the C2PA vocabulary for proving where a file came from.
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See it in the full glossary · 731 terms across 19 areas.