Color Blindness Simulator
Preview how an image looks with protanopia, deuteranopia, tritanopia or achromatopsia — 100% in your browser.
Drop an image here or click to browse
See how your design looks to viewers with colour-vision deficiency. The image is processed entirely in your browser.
🔒 The simulation runs with the Canvas API entirely in your browser — nothing is uploaded. Matrices are standard approximations, not a medical diagnosis.
Simulate colour vision deficiency
Roughly 1 in 12 men and 1 in 200 women have some form of colour blindness. This tool transforms an image to approximate how it appears to viewers with the common types — protanopia (reduced red), deuteranopia (reduced green), tritanopia (reduced blue), and achromatopsia (no colour) — so you can check whether a chart, UI, or design stays readable.
The image is processed entirely in your browser with the Canvas API and standard colour-transform matrices; nothing is uploaded. Compare the original and simulated versions side by side and download the result.
Frequently asked questions
Are these simulations medically accurate?
They use the standard matrices web accessibility tools rely on and are good for design checks, but they are approximations — not a medical diagnosis.
Is my image uploaded?
No. The transform runs with the Canvas API entirely in your browser and the image never leaves your device.
Which type should I test?
Deuteranopia and protanopia (red–green) are the most common, so test those first; tritanopia and achromatopsia are rarer but worth a check for critical visuals.