About ColorblindSimulator.app
ColorblindSimulator.app is a free set of tools for testing color vision deficiency. You can simulate how images, live websites, color palettes, and your own camera feed look to people with color blindness, and take an Ishihara-style color vision test — all in your browser, with nothing to install and no account to create.
The goal is simple: give designers, developers, educators, and anyone curious a fast, honest way to see color the way a color-blind person does. Around 1 in 12 men and 1 in 200 women have some form of color vision deficiency, and a color-only design choice can quietly leave them out. These tools help catch that early.
Two things we care about. First, privacy: image and webcam processing runs on your device, so your files are never uploaded or stored. Second, accuracy: the simulations use color-vision models from published research rather than a rough filter, and we're upfront that a simulator approximates color-blind vision and can't diagnose anyone.
About the author
ColorblindSimulator.app is built and maintained by Zakaria Amzdak, a web developer who works on accessibility tools. He started the project to give designers and developers a fast, private way to check whether their work holds up for people with color vision deficiency — without sending files to a server or paying for a subscription. Every tool on the site is free, runs in the browser, and is based on published color-vision research.
For questions, suggestions, or partnership inquiries, please contact us.