Contrast checker — WCAG 2 + APCA explained

The contrast checker (/tools/contrast-checker) scores any pair of colors against two standards at once:

• WCAG 2 — the official accessibility standard. Pass thresholds are 4.5:1 for body text and 3:1 for large text. AAA is the stricter tier.
• APCA (Lc) — the forthcoming WCAG 3 algorithm. More perceptually accurate, especially on dark backgrounds.

The "auto-fix to AA" button nudges the foreground in OKLCH until the pair clears WCAG AA — preserving hue where possible.

New: pick a font in the preview panel to see the contrast in your actual production typeface.