See an image as people with colour blindness do

About 1 in 12 men and 1 in 200 women have some form of colour blindness. See how an image, chart or design looks to them, so you can make sure nothing important depends on colour alone.

Drop an image hereAdd an image

JPG, PNG, WebP, GIF or AVIF, up to 80 MB. You can also paste an image.

Result previewOriginal image

Processed on your device. Your image is never uploaded.

How it works

  1. Your browser converts the image’s colours to linear light, the way the eye’s cones respond to them.
  2. A standard matrix removes or weakens one kind of cone (red, green or blue), or all colour for monochromacy.
  3. The result is converted back and shown next to the original.

Supported formats

Opens
JPG, PNG, WebP, AVIF, BMP and GIF (the first frame of an animation)
Saves
The simulated image, in the same format or JPG, PNG or WebP
Limits
Files up to 80 MB. The saved image can be up to 16.7 megapixels on iPhone and iPad, 36 on Android and 64 on computers, and 16,384 pixels on its longest side.
  • Uses the Machado, Oliveira and Fernandes (2009) model, applied in linear light, which is widely used in accessibility tools. Lower severities are an approximation.
  • A simulation, not a diagnosis: people’s colour vision varies.

Your image stays on your device

This tool runs entirely in your browser. The image is never uploaded, so there is nothing for us to store, see or delete.

To check, open your browser’s developer tools, switch to the Network tab and use the tool: you will not see your image being sent anywhere.

Questions

Are my images uploaded anywhere?

No. The image is read and processed by your own browser. Nothing is sent to our servers, so there is no copy of your image anywhere but your own device.

How do I make a chart work for colour-blind readers?

Don’t rely on colour alone: add labels, patterns or different shapes. Avoid red against green, and check the chart here with deuteranopia and protanopia.