Preview colors as people with color vision deficiency see them.
Loading Color Blindness Sim…
How to use Color Blindness Sim
Open the Color Blindness Sim tool.
Paste or type your color value into the input field.
The output updates as you type. Adjust the options if you need a different format.
Copy the result, or share the URL to hand the exact input to someone else.
About Color Blindness Sim
Preview how a color and a reference palette appear under different types of color blindness (protanopia, deuteranopia, tritanopia and achromatopsia) side by side with normal vision. A quick accessibility sanity check for UI palettes.
It's an approximation for design review, not a medical diagnostic tool.
What people use it for
Check whether your status colors stay distinguishable for color-blind users.
Review a palette across common CVD types before shipping.
Frequently asked questions
Which vision types are simulated?
Protanopia, deuteranopia, tritanopia and achromatopsia, alongside normal vision.
Is it medically accurate?
No, it's a simulation for design review, useful but approximate.
Is it private?
Every calculation happens on this page, in your own browser. Your input is never sent to a server and never logged, which also means the tool keeps working when you are offline.