Colour Blindness Simulator
Upload any image to see how it appears to someone with different types of colour vision deficiency. All processing happens in your browser — your image is never uploaded to any server.
Upload your image
Drop an image here
or click to browse · JPG, PNG, WebP up to 10 MB
Active Filter
Normal
Standard colour vision
Simulated view
Your simulated image will appear here after uploading.
Protanopia
Red-blind (missing L-cones)
Deuteranopia
Green-blind (missing M-cones)
Tritanopia
Blue-blind (missing S-cones)
Achromatopsia
Complete colour blindness
About this colour blindness simulator
How it works
This simulator uses scientifically-validated colour transformation matrices (based on the work of Machado, Oliveira & Fernandes, 2009) to transform each pixel's colour as it would appear to a person with each type of colour vision deficiency. All calculations happen locally in your browser using the HTML5 Canvas API.
Who uses this tool
Designers and developers use this tool to test whether their UI, infographics, charts, or marketing materials are accessible to the approximately 300 million people worldwide living with colour vision deficiency. It is particularly useful for WCAG accessibility compliance testing.
Protanopia
~1%
Red-blind. Missing long-wavelength (L) cones.
Deuteranopia
~1%
Green-blind. Missing medium-wavelength (M) cones.
Tritanopia
<0.01%
Blue-blind. Missing short-wavelength (S) cones.
Achromatopsia
<0.003%
Complete colour blindness. Sees only in greyscale.