WCAG 2.1 contrast ratio thresholds
WCAG Level AA requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text (18pt+ or 14pt bold). WCAG Level AAA requires 7:1 for normal text and 4.5:1 for large text.
Relative luminance calculation
Contrast ratio is calculated using relative luminance L = 0.2126×R + 0.7152×G + 0.0722×B where sRGB components are linearized.
Getting a trustworthy result
Color Contrast Checker & Palette Designer runs entirely in your browser from the numbers you enter. Check the methodology notes above, then compare with a related calculator or a short guide if you want a second pass before you decide.
What to do next
If prices or rates sparked this visit, glance at Markets. If you want a walkthrough, open a related guide. Or switch to another calculator in the same category to finish the task in one sitting.
FAQ
What is a passing score for web accessibility?
A contrast ratio of 4.5:1 or higher passes standard WCAG Level AA for normal body text.
Can I generate complementary and triadic color schemes?
Yes, the harmonic palette generator outputs complementary, monochromatic, and analogous color codes.
Is the Color Contrast Checker & Palette Designer free?
Yes. It runs in your browser with no account required.
Where should I go after using this tool?
Try related tools in the sidebar, Markets for live-style price snapshots, or Blog guides that link back into calculators.