Color Blindness Simulator

Check a design, chart or photo as people with color vision deficiency see it.

Drop an image here

or click to choose one — a screenshot, a chart, a photo. Or test the color list below.

VisionHow your colors look

● Your files are processed locally in your browser and are not uploaded to our servers.

How it works

The simulation uses the physiologically based model of Machado, Oliveira and Fernandes (2009), applied in linear RGB. Protanopia and deuteranopia (red-green deficiencies) affect about 1 in 12 men; tritanopia (blue-yellow) and achromatopsia (no color) are rare. Lower the severity to simulate milder forms (protanomaly, deuteranomaly).

FAQ

How do I make my design color-blind friendly?

Don't rely on color alone: add labels, icons or patterns, and check that important colors still differ in lightness.