Color Contrast Checker

The tool accepts two colors in hex, RGB, or named formats. It normalizes inputs, computes relative luminance, and returns the contrast ratio. Common outputs include a numeric ratio and a simple pass/fail status for WCAG AA and AAA targets. Example: foreground #000000 on background #FFFFFF yields 21:1, clearly passing both targets.
Under the hood it uses standard sRGB gamma correction and WCAG-compliant formulas. Luminance is calculated from linear RGB components, then contrast ratio is computed as (L1+0.05)/(L2+0.05), with higher L1 for the lighter color. It also flags non-ideal color pairs and explains why.
Audience includes UI/UX designers, front-end developers, accessibility engineers, and content strategists who need quick checks during palette selection, copy changes, or theme adjustments. It supports batch checks through multiple input pairs and returns a structured report.
Unique differentiators include explicit AA/AAA guidance, automatic color adjustment suggestions to approach accessibility targets, and strict adherence to WCAG 2.1/2.2 standards. Use cases: validate palettes, refresh marketing materials, or validate accessible typography across devices and brightness settings.