Free • private • accessibility-minded

Color Blindness Simulator Online

Upload an image and see how its colors may appear with common color vision deficiencies. Compare views instantly, inspect every mode together and download a simulated copy.

Drop an image here

or choose a JPG, PNG, WebP or GIF from your device

You can also paste an image • up to 20 MB • nothing is uploaded
Your imageReady to simulate
Deuteranopia preview
OriginalDeuteranopia
Drag the divider to compareLive browser preview
WOW VIEW

One image. Four different color experiences.

OriginalFull color reference
DeuteranopiaGreen-blind preview
ProtanopiaRed-blind preview
TritanopiaBlue-blind preview

Private by design: your image is processed locally and never leaves this browser.

Test image colors for accessibility online

This free online color blindness simulator helps designers, developers, educators and content creators spot color combinations that may be difficult to distinguish. Upload a screenshot, chart, UI mockup, map, photo or graphic, then preview common color vision deficiencies without installing software.

Compare with one drag

Slide between the original and simulated image to find exactly where important color differences disappear.

See every key view

Open the four-panel wow view to compare original, deuteranopia, protanopia and tritanopia at once.

Private browser processing

Your image stays on your device. Canvas technology applies every simulation locally, with no upload or account.

How to use the color blind simulator

1

Upload or paste an image

Choose a JPG, PNG, WebP or GIF, drag it onto the page, or paste a screenshot from your clipboard.

2

Select a vision type

Switch between protanopia, deuteranopia, tritanopia, achromatopsia and partial deficiency previews.

3

Compare and improve

Drag the divider, inspect all views, then revise colors or download the simulated PNG for your team.

What do the simulation types mean?

Deuteranopia and deuteranomaly

These affect sensitivity to green light and can make some reds, greens, browns and oranges appear more alike.

Protanopia and protanomaly

These affect sensitivity to red light. Reds may appear darker, and red-green differences can be reduced.

Tritanopia and tritanomaly

These less common blue-yellow deficiencies can make blues and greens, or yellows and pale colors, harder to separate.

Achromatopsia

This rare simulation removes color to help reveal whether contrast, shape and labels still communicate the content.

Important: A simulator is an approximation for accessibility review, not a diagnosis or a perfect representation of any one person’s color perception.

Color blindness simulator FAQ

How can I simulate color blindness on an image online?

Upload, drop or paste your image, then select a color vision type. The preview updates instantly. Drag the comparison divider to reveal the original, or choose “See all views” to compare four versions together.

Is this online color blind simulator free?

Yes. It is completely free, requires no account and adds no watermark. You can test and download as many images as you need.

Are my uploaded images private?

Yes. Every simulation runs locally in your browser. The tool does not upload, store or share your image.

What image formats does the simulator support?

You can use JPG, PNG, WebP and GIF images up to 20 MB. For animated GIFs, the browser-displayed frame is used for the simulation.

Which color vision deficiencies can I preview?

You can preview deuteranopia, protanopia, tritanopia, achromatopsia, deuteranomaly, protanomaly and tritanomaly. The strength control also lets you blend each effect with the original.

Can this replace accessibility testing with real users?

No. It is a fast way to identify likely color problems, but it should complement contrast checks, non-color cues and feedback from people with color vision deficiencies.

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