Color blindness simulator
Shows how your image looks to people with color vision deficiency: protanopia, deuteranopia, tritanopia, achromatopsia.
Applies a matrix transform that simulates how people with different types of color vision deficiency perceive your image. Four variants: protanopia (no red cones, ~1% of men), deuteranopia (no green cones, the most common full form — “red-green colorblindness”), tritanopia (no blue cones, rare) and achromatopsia (full monochrome, very rare). A severity slider (0–100%) lets you also check the partial forms (anomalous trichromacy — deuteranomaly etc. — actually more common than the full forms: about 8% of men and 0.5% of women for deuteranomaly). Below the result is a before/after slider: drag it to see how the image transforms. Useful for designers (whether colors in mockups, icons, charts and status indicators remain distinguishable) and accessibility auditors (red/green indicators in dashboards, chart series in reports). The algorithm uses the Machado, Oliveira, Fernandes (2009) matrices — an industry standard, used by Chrome DevTools “Emulate vision deficiencies”; applied in linear RGB via gamma-correct sRGB conversion, which gives a more accurate result than “direct” matrix multiplication on gamma-encoded pixels. Processing happens in the browser, the file never leaves your device.