Color Blindness Simulator

Drop or paste an image and see it through the eyes of every common colour-vision deficiency — protanopia, deuteranopia, tritanopia, and achromatopsia. Side-by-side previews, a swatch test row so you can tell the simulations apart at a glance, and one-click PNG download of each. Pure client-side, no upload.

Drop, paste, or pick an image.
About the simulations

Each simulation uses the Machado, Oliveira & Fernandes (2009) matrices for dichromacy, applied per-pixel in linear-light sRGB (with proper gamma decode → matrix → gamma encode). For achromatopsia we collapse to the Rec. 709 luma weights (0.299 R + 0.587 G + 0.114 B).

These are the same matrices used by Sim Daltonism, Chrome DevTools' vision-deficiency emulation, and most accessibility tooling. They are a useful approximation, not a clinical model — every person with colour-vision deficiency sees things a little differently.

Prevalence figures are rough averages for populations of Northern European descent. Other populations have different distributions — deuteranopia, for example, is roughly half as common in sub-Saharan African populations.