Check colour contrast against WCAG 2.1 AA and AAA, with a live text preview and the closest passing colour when a pair fails. Free, no signup.
First time here? Enter or pick your text colour Your input is processed locally and disappears when you close the tab.
Low-contrast text is the most common accessibility failure on the web and the easiest to fix, because unlike most accessibility work it is a number you can check in seconds. This free WCAG contrast checker gives you that number and tells you what to do when it is too low.\n\nEnter a text colour and a background and you get the ratio, from 1:1 for identical colours up to 21:1 for black on white, checked against every level that matters: AA and AAA for both normal and large text, plus the 3:1 threshold for interface components like form borders and icons that people often forget applies at all.\n\nA live preview shows real text at three sizes on your actual colours, because a ratio is abstract and seeing the paragraph is not. When a pair fails, the tool suggests the closest passing colour — the smallest shift from your original that clears AA, darkening on light backgrounds and lightening on dark ones, keeping your hue rather than defaulting to black.\n\nThis matters commercially as well as ethically: accessibility legislation across the EU, UK and US references WCAG, and AA is the level usually cited. Everything runs in your browser. Pair it with the HEX to RGB Converter for format conversion, or the Colour Palette Generator when you are building a scheme from scratch.
Enter or pick your text colour
Enter or pick your background colour
Read the ratio and the AA/AAA results
If it fails, apply the suggested passing colour
Large heading text
Body copy at a normal size. This is the paragraph a visitor actually has to read, so it is the one that has to clear 4.5:1.
Smaller supporting text, often used for captions and hints.
Ratios run from 1:1 (identical) to 21:1 (black on white). WCAG 2.1 requires 4.5:1 for body text and 3:1 for large text — large meaning 18pt and up, or bold from 14pt.