What is WCAG color contrast?+
WCAG (Web Content Accessibility Guidelines) defines minimum contrast ratios between text and background colors to ensure readability for people with visual impairments. The contrast ratio ranges from 1:1 (no contrast) to 21:1 (maximum contrast, black on white).
What contrast ratio do I need?+
For WCAG AA compliance: 4.5:1 for normal text and 3:1 for large text (18pt+ bold or 24pt+ regular). For WCAG AAA (enhanced): 7:1 for normal text and 4.5:1 for large text.
How is contrast ratio calculated?+
Contrast ratio is calculated using the relative luminance of the two colors. The formula is (L1 + 0.05) / (L2 + 0.05), where L1 is the lighter color's luminance and L2 is the darker color's luminance.
Is color contrast legally required?+
In many jurisdictions, yes. The ADA (Americans with Disabilities Act) and similar laws in other countries require websites to be accessible. WCAG 2.1 Level AA is the most commonly referenced standard.