Colour Blindness Simulator
See any photo as people with protanopia, deuteranopia, tritanopia or achromatopsia see it.
This simulator lets you see an image approximately the way people with different types of colour vision deficiency see it. You can upload your own photo or use one of our sample images, then switch between four views: protanopia (no functioning red-sensitive cones), deuteranopia (no functioning green-sensitive cones), tritanopia (no functioning blue-sensitive cones) and achromatopsia (complete absence of colour vision, seeing in shades of grey).
It is useful for parents and teachers who want to understand a child's experience, for designers checking whether charts, maps, signs or websites still work without relying on colour alone, and for anyone curious about how colour vision works. Your image is processed entirely in your browser using standard colour transformation models; it is never uploaded to our server.
Bear in mind that these are simulations of the most complete forms of each deficiency. Most colour-deficient people have milder forms (anomalous trichromacy), so their perception lies somewhere between typical vision and the simulated image. Individual experience also varies, and screens differ in how they show colour. The simulator is an educational and design tool; it cannot test your own colour vision. For that, try our colour vision test.
How to use
- Choose a sample image or upload a photo from your device (it stays in your browser).
- Select the type of colour vision to simulate: protanopia, deuteranopia, tritanopia or achromatopsia.
- Compare the simulated version with the original, switching between views to see which colours merge.
- For design checks, look at whether text, lines and important areas remain distinguishable in every view.
- Switch off night mode and colour filters on your screen for the most accurate impression.
Reading your result
Colours that look different in the original but nearly identical in a simulated view are the ones people with that deficiency may confuse. Red-green confusion in protanopia and deuteranopia is by far the most common, so pay most attention to those views. Reds may also appear darker in protanopia.
If you design materials, add labels, patterns, shapes or stronger light-dark contrast so that information does not depend on hue alone. If the simulated images look no different to you from the original, that alone does not mean you have a colour deficiency; use a proper colour vision test and, if needed, see an eye-care professional.
Caution: Educational simulation only. It does not diagnose colour blindness and represents the strongest forms of each deficiency, which may differ from an individual's experience.
Frequently asked questions
Is my photo uploaded anywhere?
No. The image is processed locally by your browser and is not sent to our server or stored.
Do colour-blind people really see in black and white?
Very rarely. Complete achromatopsia is uncommon; most colour-deficient people see many colours but confuse certain shades.
Why does deuteranopia look similar to protanopia?
Both affect the red-green axis, so they confuse similar colour pairs. Protanopia also makes reds look darker.