Design & colour
Colour contrast checker
Check text and background contrast against WCAG ratios.
A clear answer. Here’s how.
Calculates WCAG relative luminance and contrast ratio for opaque sRGB colours. AA requires 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1 and 4.5:1 respectively. Large means at least 18 pt regular or 14 pt bold. Passing contrast alone does not establish full accessibility.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Text colour (HEX)
- #365bd5
- Background colour (HEX)
- #ffffff
Example result
- Contrast ratio
- 5.81:1
- AA normal text
- Pass
- AA large text
- Pass
- AAA normal text
- Fail
- AAA large text
- Pass
Pass/fail uses the full-precision ratio, before display rounding.