ColorCheck — CVD Accessibility Scanner

About

ColorCheck scans the visible tab and the live DOM to find color combinations that fail for the 350+ million people with color vision deficiency (CVD). Works on production sites, staging, and localhost.

What you get
• Accessibility score — a single 0–100 number summarizing how well your colors hold up under CVD
• Palette analysis — top dominant colors extracted from a screenshot, checked pairwise under protanopia, deuteranopia, and tritanopia
• Flagged elements — a list of specific DOM elements (with selectors) whose text fails WCAG contrast or breaks under color-blindness simulation
• Severity grading — high / medium / low so you can fix what matters first

Built for designers + developers
• One click — no setup, no DevTools panel
• Works on any URL, including localhost and staging environments
• Uses scientifically-validated Brettel CVD simulation matrices and WCAG 2.1 contrast formulas
• Companion to colorcheck.dev — get full multi-page reports, AI palette fixes, and PDF exports on the web app

Privacy first
Nothing leaves your machine. We never send page content, screenshots, or scan results to a server. The license activation is the only network call. See full privacy policy: https://colorcheck.dev/extension-privacy

Pro feature
Requires an active Pro subscription on colorcheck.dev. Sign up at https://colorcheck.dev/pricing, then reveal your license key in your account.