The free Color Blindness Simulator
Free color blindness simulator. Upload an image or screenshot and see it as people with protanopia, deuteranopia, tritanopia or achromatopsia see it.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
A red/green status chart under deuteranopia → both colours look olive-brown: add labels or icons.Open the Color Blindness Simulator
Illustration. Open the tool for the real thing.
What is the Color Blindness Simulator?
About 1 in 12 men and 1 in 200 women have some form of colour-vision deficiency, most often trouble telling reds from greens. If your chart, map, button or graphic relies on colour alone, they may not be able to read it. This simulator shows your image the way people with protanopia (no red cones), deuteranopia (no green cones), tritanopia (no blue cones) or achromatopsia (no colour) see it, side by side with the original.
The transformation uses the scientifically established Machado et al. (2009) model applied in linear RGB, with a severity slider from mild to complete. Upload a screenshot, logo, chart or photo, switch between types, and download the simulated image. It runs entirely in your browser, so unpublished designs stay private.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
Protanopia, deuteranopia, tritanopia and achromatopsia.
From mild colour weakness to full deficiency.
Original next to the simulation.
Machado 2009 matrices applied in linear RGB.
AZRS tools are free to open and use.
It opens in your browser, so there is nothing to download.
Used for
Pick one to see how it fits.
How it compares
A plain look at this tool next to the usual alternative.
| This utility | Desktop software | |
|---|---|---|
| Install | Nothing to install | Usually an app or program to install |
| Account | No signup | Depends on the product |
| Cost | Free to use | Free or paid, depends on the product |
| Where it runs | In your browser tab | On your computer |
Questions people ask
How accurate is the simulation?
It uses the published Machado et al. (2009) model, widely used in accessibility tools, but real perception varies between people.
Is my image uploaded?
No. Processing is local.
What is deuteranopia?
The most common deficiency: green cones do not work, so reds and greens look similar.
Can this test if I am colour blind?
No. It shows what others see; use an Ishihara-style test or an optometrist to test your own vision.
What is the severity slider?
It blends between normal vision (0%) and complete deficiency (100%) for milder colour weakness.
More free tools
Related to the Color Blindness Simulator.
Try the Color Blindness Simulator now
See any image as people with protanopia, deuteranopia or tritanopia see it. Free to use.
Try it free