Color Blindness Simulator — preview images & colors
Simulate protanopia, deuteranopia, tritanopia and achromatopsia on any image or color to check accessibility — all in your browser.
🔒 Runs entirely in your browser. Your input and output are never sent to a server or stored — fully private.
🔒 All simulations run in your browser — your image never leaves your device.
About this tool
This color blindness simulator shows how an image or a single color appears to people with different types of color vision deficiency — protanopia, deuteranopia, tritanopia and full achromatopsia. Upload a design or pick a color, switch between the simulations, and instantly see whether your reds and greens still read clearly. It runs entirely on a canvas in your browser, so the images you test are never uploaded to a server.
Frequently asked questions
What do protanopia, deuteranopia and tritanopia mean?
They are the main types of color vision deficiency: protanopia and deuteranopia both make reds and greens hard to tell apart, while tritanopia affects blues and yellows. Achromatopsia is the rare case of seeing no color at all, in shades of gray. Simulating each one shows where a design might confuse a real viewer.
Why should I check my design for color blindness?
Around one in twelve men and one in two hundred women have some form of color vision deficiency, so a chart or button that relies on red-versus-green alone can be unreadable to them. Previewing your work here helps you add labels, patterns or contrast so the meaning never depends on color alone.
Are the images I test uploaded anywhere?
No. The simulation is applied on a canvas in your browser, so the images and colors you check stay on your device and are never sent to or stored on a server.