Color Blindness Simulator
Preview how an image looks with protanopia, deuteranopia, tritanopia or achromatopsia.
This is an approximate simulation (Machado et al., 2009). Real color vision differs between people and screens.
Is your design readable for everyone?
Around 8% of men and 0.5% of women have some form of colour vision deficiency. Charts separated only by red and green, error messages marked only by colour or map legends can become impossible to tell apart. The simulator recolours your image as it would appear with different types of colour vision so you can spot problems early.
Simulated types
- Protanopia: missing red-sensitive cones
- Deuteranopia: missing green-sensitive cones, the most common type
- Tritanopia: missing blue-sensitive cones
- Achromatopsia: complete colour blindness
A split view compares the original and the simulation side by side. The simulation is based on the scientific model by Machado et al. (2009) and runs in your browser.
How to use Color Blindness Simulator
- Upload the chart, UI design or image to test.
- Choose the simulation type.
- Compare original and simulation in the split view.
- Optionally download the simulated image to share with your team.
Why use this tool?
Test designs before launch for accessibility (WCAG), a wider audience and fewer user errors.
FAQ
How accurate is the simulation?
It uses the Machado et al. (2009) model for full dichromacy. Real perception varies by person and screen, so treat it as an approximation.
How can I make designs better for colour-blind users?
Don't convey information through colour alone; add patterns, icons, labels and enough brightness contrast.
Which type is most common?
Deuteranopia and its milder form, deuteranomaly, are the most common colour vision deficiencies.
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