Perceivable / 1.4 Distinguishable
1.4.3Contrast (Minimum)
Level AAMaintain a contrast ratio of at least 4.5:1 between text and its background, or 3:1 for large text (18pt or larger, or 14pt bold or larger). Purely decorative text, logos or brand names, and inactive UI components are exempt from this requirement.
Note
A detailed commentary for this success criterion is not yet available. In the meantime, this page lists related patterns, techniques, and links to the normative sources.
Related Techniques
Specific implementation techniques for meeting this success criterion. This site doesn't include the full text, so follow the links to the original W3C documents.
Sufficient Techniques(4)
- G18: Ensuring that a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text(opens in a new tab)waic.jp(opens in a new tab)
- G145: Ensuring that a contrast ratio of at least 3:1 exists between text (and images of text) and background behind the text(opens in a new tab)waic.jp(opens in a new tab)
- G148: Not specifying background color, not specifying text color, and not using technology features that change those defaults(opens in a new tab)waic.jp(opens in a new tab)
- G174: Providing a control with a sufficient contrast ratio that allows users to switch to a presentation that uses sufficient contrast(opens in a new tab)waic.jp(opens in a new tab)
Advisory Techniques(1)
Failures(2)
- F24: Failure of Success Criterion 1.4.3, 1.4.6 and 1.4.8 due to specifying foreground colors without specifying background colors or vice versa(opens in a new tab)waic.jp(opens in a new tab)
- F83: Failure of Success Criterion 1.4.3 and 1.4.6 due to using background images that do not provide sufficient contrast with foreground text (or images of text)(opens in a new tab)waic.jp(opens in a new tab)
Normative References
- Success Criterion 1.4.3 Contrast (Minimum) — WCAG 2.2(opens in a new tab)The normative requirement text.
- Understanding Contrast (Minimum) — W3C(opens in a new tab)Official guidance on intent, examples, and techniques.