Contrast Checker
Check the WCAG contrast ratio between foreground and background colors. Free.
What is a contrast checker?
A contrast checker measures the difference in brightness between two colors — typically text and its background — and tells you whether the combination passes the WCAG accessibility guidelines. Good contrast is what keeps text readable for everyone, including people with low vision or color blindness.
Pick a foreground and a background color, and the tool instantly computes the contrast ratio and the WCAG rating: AA and AAA for normal and large text. Everything runs locally in your browser.
How to use the contrast checker
- Choose the text color and the background color.
- Read the contrast ratio and the WCAG rating.
- Adjust colors until you reach AA or AAA for the text size you use.
Frequently asked questions
What is WCAG?
The Web Content Accessibility Guidelines — the standard that defines how much contrast text needs to be readable. AA and AAA are the two passing levels.
What ratio is AAA?
AAA requires a contrast ratio of at least 7:1 for normal text and 4.5:1 for large text. AA requires 4.5:1 for normal and 3:1 for large text.
Can I enter my own HEX values?
Yes — paste any HEX color into the inputs and the ratio recalculates instantly.
Is it free?
Yes — free with no limits, no signup, and everything runs in your browser.