Roughly 1 in 12 men and 1 in 200 women have some form of color vision deficiency. If your UI relies on color alone to communicate meaning, a real chunk of your users may not be able to tell your “success” green from your “error” red.
What Is the Color Blindness Simulator?
Upload any image — a screenshot, a mockup, a chart — and see it rendered through four common color vision deficiencies: protanopia, deuteranopia, tritanopia, and achromatopsia. Everything runs in your browser via canvas pixel manipulation; nothing is uploaded to a server.
How to Use It
- Open the tool at /tools/color-blindness-simulator.
- Drop in an image or choose one from your device.
- Click through the vision-type buttons to compare how the image renders under each condition.
Key Features
- Four simulated conditions: protanopia and deuteranopia (red/green), tritanopia (blue/yellow), and achromatopsia (full grayscale).
- Published CVD transform matrices, the same approach used in accessibility research and design tools.
- 100% client-side — your image never leaves your browser.
- Instant switching between vision types to compare side by side.
When to Use This Tool
- Accessibility testing for dashboards, charts, and status indicators that rely on color.
- Design review before shipping a UI that uses color as the only differentiator.
- Content review for infographics or data visualizations meant for a general audience.
Try It Now
Open Color Blindness Simulator directly, or press ⌘K and type the tool name from anywhere on the site.
Part of the Color Tools collection on WebdevToolbox — free, browser-based developer tools with no login required.