Color Picker & Contrast Checker
Pick and convert colors between HEX, RGB, and HSL, and check the WCAG contrast ratio between a text and background color. Runs entirely in your browser.
Text color
Background color
Large text sample
Normal-size text sample for readability.
What can you check?
HueCheck picks and converts a color between HEX, RGB, and HSL, and checks the contrast ratio between two colors against the WCAG 2.x accessibility thresholds — useful for choosing text and background colors that are readable for people with low vision, or for verifying a design meets accessibility requirements before shipping.
How it works
Edit either color using the swatch picker or by typing directly into the HEX, RGB, or HSL field — all three stay in sync. The contrast ratio is calculated using the official WCAG relative luminance formula, entirely in your browser, so nothing is ever sent to a server.
Frequently asked questions
Is this free to use?
Yes. There's no sign-up and no limit on how many colors you check.
Do you store the colors I pick?
No. Everything is calculated entirely client-side in your browser. See the privacy policy for details.
What contrast ratio do I need to pass WCAG?
For normal text, WCAG AA requires at least 4.5:1 and AAA requires 7:1. For large text (18pt+, or 14pt+ bold), AA requires 3:1 and AAA requires 4.5:1.
How is the contrast ratio calculated?
Using the WCAG 2.x formula: each color's relative luminance is calculated from its sRGB values, and the ratio is (lighter + 0.05) / (darker + 0.05).