ChromaCheck

ChromaCheck shows you what your website looks like to the 300 million people worldwide with color vision deficiency — and tells you exactly where your design is failing them. ━━━ SIMULATE REAL VISION ━━━ Apply scientifically calibrated filters to any webpage to see it through seven types of color blindness: • Green weak (Deuteranomaly) — the most common form, ~5% of men • Red weak (Protanomaly) • Green blind (Deuteranopia) • Red blind (Protanopia) • Blue weak (Tritanomaly) • Blue blind (Tritanopia) • No color vision (Achromatopsia) Plus a high-contrast assistive view for low-vision users. The simulation uses the Brettel-Viénot-Mollon (1997) and Machado et al. (2009) color projection models — the same math used in vision research. Not a tinted overlay, not a guess. The real perceptual transform. ━━━ AUDIT WHAT MATTERS ━━━ One click runs a full WCAG 2.1 contrast audit on every text element on the page: • AAA, AA, and A compliance counts • Overall compliance percentage • Specific failing elements with selectors, ratios, and text snippets • Click any failure to scroll directly to it on the page ━━━ CATCH WHAT OTHER TOOLS MISS ━━━ ChromaCheck's killer feature: it re-runs the contrast audit through each color blindness projection and flags regressions — pairs that pass for normal vision but fail under deuteranopia, protanopia, or tritanopia. This is where most accessibility issues actually live. A red-on-green "required field" indicator that looks fine to you might be invisible to the colorblind reviewer on your team. ChromaCheck finds those before they ship. ━━━ FAST AND PRIVATE ━━━ • Audits run locally in your browser. No data leaves your machine. • No accounts, no telemetry, no network requests. • No host permissions — only touches a tab when you click the icon. • Open source. ━━━ WHO IT'S FOR ━━━ • Designers and developers shipping accessible interfaces • Accessibility specialists auditing sites • Product managers reviewing what users with CVD actually experience • Anyone curious how their friend, parent, or colleague sees the web About 1 in 12 men and 1 in 200 women have some form of color vision deficiency. They're using your site right now. ChromaCheck helps you make sure they can.