Color Blindness Simulator
See how your designs look to people with Protanopia, Deuteranopia, Tritanopia, and more color vision deficiencies — free accessibility testing tool.
WCAG Accessibility
Ensure your designs are accessible to the 8% of men and 0.5% of women with color vision deficiency. Essential for compliance.
4 Simulation Types
Protanopia (red), Deuteranopia (green), Tritanopia (blue), and Achromatopsia (total) — using scientifically accurate transformation matrices.
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Frequently Asked Questions
Upload an image to Toolsz Color Blind Simulator to see how it appears to people with Deuteranopia, Protanopia, and Tritanopia. While tools like color-blindness.com/coblis have old interfaces and upload files, Toolsz provides an instant, private, client-side simulation.
Toolsz offers the best alternative to Coblis. The simulation runs entirely in your browser using Canvas, meaning it is fast, free, requires no signup, and ensures your design privacy.