Color Contrast Checker (WCAG)

Check the colour contrast between any text and background against the WCAG accessibility standards. Pick two colours and instantly see the contrast ratio plus a clear pass or fail for AA and AAA, for both normal and large text.

Why colour contrast matters

Good contrast makes your content readable for everyone, including people with low vision or colour blindness. It is also part of the WCAG accessibility guidelines, and accessibility is an increasingly important signal for search engines.

WCAG contrast requirements

• AA normal text — a ratio of at least 4.5:1.
• AA large text (18pt or 14pt bold) — at least 3:1.
• AAA normal text — at least 7:1.
• AAA large text — at least 4.5:1.

Frequently asked questions

What is a good contrast ratio?

Aim for at least 4.5:1 for body text to meet WCAG AA. Higher is better, and 7:1 meets the stricter AAA level.

What counts as large text?

Text that is at least 18pt (about 24px), or 14pt (about 18.66px) and bold. Large text is easier to read, so it has a lower contrast requirement.

Does contrast affect SEO?

Indirectly, yes. Accessibility is part of a good user experience, and tools like Lighthouse score contrast as part of the accessibility audit that feeds into overall site quality.