About ColorContrast
ColorContrast exists because "looks fine" is not a contrast ratio.
WCAG contrast is exact math: relative luminance (perceptually weighted RGB), one division, one ratio. 4.5:1 passes normal text, 3:1 passes large text, 7:1 passes AAA. The calculator runs the official formula and prints the verdicts — no screenshots, no vibes.
The converter handles the designer's daily translation: hex to RGB to HSL, with the luminance shown so palettes can be built against the contrast target directly.
We are developers and educators, not auditors. Nothing here sells accessibility overlays (please, no), and the math runs in your browser.
What makes ColorContrast different
- Your numbers never leave your browser. Every calculator on ColorContrast runs entirely on your device. We never see, store, or transmit the figures you enter — there are no accounts and no server-side processing of your inputs.
- Published methodology. Each calculator page explains the exact formula it uses and the assumptions behind it, so you can check our work or reproduce it in a spreadsheet.
- Free, forever, without a paywall. ColorContrast is supported by advertising. There is no premium tier, no email gate, and no upsell.
Independence
ColorContrast is an independent educational project. We are not affiliated with, endorsed by, or acting on behalf of any government agency, lender, insurer, or the organizations whose formulas and public data we reference (such as WCAG 2.x relative-luminance definitions). All trademarks and referenced standards belong to their respective owners.
Questions, corrections, or suggestions are genuinely welcome — get in touch.