Color Blindness Simulator

Four conditions: protanopia and deuteranopia (both affect red/green discrimination, the two most common forms of color blindness, together affecting roughly 1 in 12 men), tritanopia (a rarer blue/yellow deficiency), and achromatopsia (complete color blindness, rendered as full grayscale).

It uses published linear-RGB transform matrices commonly used in CVD simulation research and design tools — a solid approximation of how these conditions typically affect color perception. It is not a medically precise simulation of any one individual, since real-world severity varies from person to person.

Accessibility testing — if two elements (like a "success" green and an "error" red badge) become visually indistinguishable under protanopia or deuteranopia simulation, colorblind users likely can't tell them apart either, and you should add a non-color cue (icon, text label, pattern).

No — the image is loaded into an in-memory canvas and processed entirely in your browser using JavaScript pixel manipulation. Nothing is uploaded to a server.

This tool is built around image uploads so you can test real screenshots, mockups, or photos. For checking two specific colors against each other for contrast, pair it with the Color Contrast Checker tool instead.