What is a good contrast ratio?
Contrast ratio runs from 1:1 (no contrast) to 21:1 (black on white). WCAG 2.1 requires at least 4.5:1 for normal text and 3:1 for large text and UI components to meet level AA; level AAA requires 7:1 and 4.5:1. Higher is more readable, especially for low‑vision users and in bright light.
Frequently asked questions
- What contrast ratio is accessible?
- For level AA, normal text needs at least 4.5:1, while large text and UI components need at least 3:1. Level AAA raises those thresholds to 7:1 and 4.5:1.
- What is large text?
- Large text is roughly 18px bold or 24px regular and up (precisely, ≥18.66px bold or ≥24px regular).
- Does this follow WCAG?
- Yes — the ratio uses the WCAG 2.1 contrast math (relative luminance with the standard thresholds).