Calculate exact contrast ratios between foreground text and background colors with AA/AAA pass/fail badges for normal text, large text, and UI components.
Good design is as little design as possible. High contrast guarantees readability for all users, including those with visual impairments or working under direct sunlight.
Contrast Checker is an air-gapped developer utility designed for maximum precision, client-side speed, and uncompromising privacy. Every operation executes entirely within your browser memory.
All computations run locally inside your browser. No strings, tokens, or files are ever transmitted to any remote servers.
Changes update asynchronously in real time as you type, with zero network lag or server queue delays.
Easily copy outputs, download formatted artifacts, or share local configurations using browser-safe states.
Fully functional without an active internet connection. Work safely on planes, trains, or air-gapped networks.
Quickly test, validate, and iterate on contrast checker workflows during development without running heavy local scripts.
Safely paste sensitive production telemetry or configuration fragments into an isolated sandbox to diagnose issues rapidly.
Achieve standard-compliant, deterministic results regardless of whether you're working on macOS, Linux, or Windows.
Comply with strict enterprise security guidelines where customer data cannot be pasted into cloud web utilities.