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Free Color Blindness Simulator

See how your design looks to people with color vision deficiencies. Simulates protanopia, deuteranopia, tritanopia, achromatopsia, and milder anomalies.

No file size limitFiles stay privateNo login requiredFree forever

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JPG, PNG, WebP no file size limit

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Your files never leave your device. All processing happens locally in your browser.

Upload a design, infographic, or photo to see how it appears to people with color vision deficiencies. Especially useful for: chart designers, UX designers, and accessibility audits.

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How It Works

Color vision deficiency (CVD) is simulated using Brettel-Viénot color transformation matrices — the standard algorithm used in accessibility tools.

1
You drop an image
The image is loaded into a canvas in your browser. Pixels are downsized for performance (max 1200 px on the longest edge).
2
A 3×3 color transform is applied to every pixel
Each CVD type has a specific matrix. For deuteranopia (green-blind), red and green channels get mixed in a way that mimics what people with only L+S cones perceive.
3
The transformed image displays alongside the original
Switch between CVD types to see how the same image looks for the ~8% of men with some form of color vision deficiency.

Your image stays in your browser. Even the simulation math runs locally on your CPU — no server, no API, no upload.