What is the minimum contrast ratio for WCAG AA?

WCAG AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (18pt or 14pt bold).

What does WCAG AAA require?

AAA requires a ratio of at least 7:1 for normal text and 4.5:1 for large text. AAA compliance is harder to achieve and is typically a stretch goal.

WCAG 1.4.11 requires a 3:1 ratio for UI components and graphical objects. This tool checks for that level when you select the UI component mode.

The tool calculates the relative luminance of each color using the WCAG formula, then divides the lighter luminance by the darker to get the ratio.

Enter foreground and background colors to get the contrast ratio and WCAG pass/fail result.

Foreground

Background

Last updated: 2026-06-10 · Reviewed by Nham Vu