Color Blindness Simulator
See how a picture looks with color vision deficiency. Pick a sample or upload your own photo, choose a type, and drag the severity slider.
🔒 Everything here runs in your browser. Photos you upload are processed on your device with a canvas and never sent to any server.
How the simulation works
Each view applies a color-transform matrix that approximates how the three cone types respond in deutan (green-weak), protan (red-weak), and tritan (blue-yellow) vision. We use the widely-cited Viénot and Brettel methods, the same approach used in accessibility tooling. It's an approximation of the average case, not a personal diagnosis, and how it looks also depends on your own screen's colors.
Want to check your own color vision instead? Take the free color blind test, or read how colorblind people see.
Frequently asked
Is this color blindness simulator accurate?
It uses the same dichromat simulation matrices (Viénot/Brettel) that vision researchers use to approximate how a photo looks with deutan, protan, or tritan vision. It's a close approximation, not a medical instrument, and results depend on your screen.
Are my uploaded photos private?
Yes. All processing happens in your browser on a canvas element. Photos you upload never leave your device and are not sent to any server.
What does the severity slider do?
It blends between normal vision (0%) and full dichromacy (100%) to approximate milder, anomalous forms of color vision deficiency in between.
Sample images are simple illustrations created for this tool (public domain / CC0). Your own uploads are processed locally and never stored.