Colour contrast checker

The contrast ratio of two colours and whether it passes WCAG 2 for body text, large text and interface parts.

Runs in the browser. Nothing is sent or stored.
Uses the WCAG 2 contrast formula, the one accessibility audits and legal standards refer to.
Suggests the nearest text colour that passes, keeping the hue and changing only lightness.

Questions

What do AA and AAA mean?

Two WCAG conformance levels. AA is the usual target and the level most accessibility rules ask for: 4.5:1 for body text, 3:1 for large text. AAA is stricter: 7:1 and 4.5:1.

Does it matter for a small business site?

Yes, for readers first: grey text on white that looks elegant on a good screen is hard to read in sunlight or for tired eyes. It also feeds into accessibility rules that apply to more businesses each year.

Is a passing ratio always readable?

Not always. The ratio ignores font weight, size and thin strokes. It is a floor, not a guarantee: always look at the real text.

These tools are free and provided as they are. They are made with care, but they are not guaranteed to be free of errors or to suit every purpose, and they are used at the user's own responsibility. Please check the result before relying on it: scan the code, confirm the payment details, and where it matters ask the recipient or an adviser. To the extent permitted by law, Broken Logic Studio is not liable for loss or damage arising from the use of the tools.