Large text contrast (3:1): Crawl Audit check 174

Short answer: big text is easier to read, so WCAG lets it have less contrast: 3 to 1 instead of 4.5 to 1. That's why a pale headline can pass while the same colour fails as body text. Check 174 warns when Lighthouse reports contrast problems.

What Crawl Audit checks

• Full audit: it reads the same Lighthouse contrast audit as check 173. Pass if nothing fails; warning if anything does.
• Free check: not tested, and passes.

Lighthouse already applies the lower 3:1 limit to large text and 4.5:1 to the rest, then reports one result. So checks 173 and 174 pass or fail together; 174 is the softer warning.

What counts as large

• WCAG: "Large-scale text and images of large-scale text have a contrast ratio of at least 3:1".
• Large means "at least 18 point or 14 point bold". W3C converts that to "approximately 18.5px and 24px": 18.5 pixels if bold, 24 pixels if not.
• Thin or decorative fonts can look smaller than their size suggests. If in doubt, use 4.5:1.

On devmarde.com

After the colour fix described in check 173, Lighthouse found no contrast failures on our homepage on 6 October. It passes.

Sources

• W3C, Understanding 1.4.3 Contrast (Minimum) (updated 6 September 2026), checked 6 October 2026.