Simulate color blindness on any image — protanopia, deuteranopia, tritanopia — free online.
About
Simulates how an image looks to someone with one of four common types of color vision deficiency — protanopia, deuteranopia, tritanopia or achromatopsia — by remapping its colors the way that condition would perceive them, then lets you download the result as a PNG.
Designers and product teams use it to check whether a chart, icon set or interface still reads clearly for colorblind users before shipping it, while educators use it to demonstrate what color vision deficiency actually looks like. It joins Toolapt's other free designer tools, with no account required and no cap on how many times you come back to use it.
Examples
3 worked examples
Applying protanopia to a bar chart with red and green bars turns the green bars dark grey and the red bars a muddy olive, so profit and loss become hard to tell apart — a sign the chart needs labels or patterns, not colour alone.
Applying deuteranopia to a red-and-green logo turns the red into olive-yellow and the green into a dull grey-violet, showing how differently the brand reads for someone with green-blindness.
Applying achromatopsia to a colour photo of tulips renders it entirely in shades of grey, simulating complete colour blindness — download it as colorblind-simulation.png.
FAQ
Quick answers to common questions about the Colour Blindness Simulator.
It remaps an image's colors to simulate how someone with protanopia, deuteranopia, tritanopia or achromatopsia would perceive it, and lets you download the result.
Yes. It's free, with no sign-up, no watermark and no limit on how many times you use it.
Yes. The simulation runs entirely on your own device using your browser's built-in Canvas API — your image is never uploaded to a server.
Protanopia and deuteranopia are red-blind and green-blind respectively — the two most common forms, often grouped as "red-green" color blindness. Tritanopia is blue-blind and much rarer. Achromatopsia is complete color blindness, seeing only in shades of gray.
It's a close, widely used approximation based on how each condition's altered color perception works, not a perfect physiological match — individual experiences of color vision deficiency vary.
Yes. The original stays in the upload area above the canvas, so you can look between the two, and you can re-run the simulation with a different type at any time.
Yes. The page is fully responsive and works on mobile, tablet and desktop browsers alike.
It simulates the four most commonly discussed types of color vision deficiency; it doesn't cover every rare variant of color blindness.
Did Colour Blindness Simulator work for you?