Which simulation matrices are used?

Standard Viénot-style 3×3 RGB transforms for each deficiency. They approximate how a person with that condition perceives colors — not a perfect model but the de-facto reference for design testing.

Why should designers care?

About 8% of men and 0.5% of women have some form of color vision deficiency. If your design relies solely on red/green contrast, key information may be invisible to them.

Is this a medical simulation?

No. It's a design-tool approximation. For clinical color-vision testing, see an optometrist.

Is my image uploaded?

No. Simulation runs entirely in your browser.

Color Blindness Simulator

Preview how your image looks to users with 8 color-vision deficiencies.

100% private — no uploads Image ToolsFree & unlimited Read tutorial

How to use Color Blindness Simulator

Follow these steps — everything happens instantly in your browser.

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Step 1. Drop an image onto the zone.
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Step 2. Pick a color vision deficiency type (deuteranopia is the most common).
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Step 3. Click “Download simulated image” to save the result.