The Definitive WCAG 2.1 Color Contrast Guide
Everything you need to know about AA vs. AAA compliance, luminance formulas, and inclusive design standards.
1. WCAG 2.1 Compliance Levels
- Level AA (Minimum): Requires 4.5:1 contrast for normal body text and 3.0:1 for large text (18pt+ or 14pt bold). This is the legal accessibility requirement for most public websites.
- Level AAA (Enhanced): Requires 7.0:1 contrast for normal text and 4.5:1 for large text. Recommended for long-form reading and mission-critical government/medical dashboards.
2. Color Blindness Consideration
Over 300 million people worldwide have color vision deficiency. Never rely on color alone (such as green vs. red) to convey state without accompanying icons, text labels, or distinct luminance contrast.