Coblis —
Color Blindness Simulator

If you are not suffering from a color vision deficiency it is very hard to imagine how it looks like to be colorblind. The Color BLIndness Simulator can close this gap for you. Just play around with it and get a felling of how it is to have a color vision handicap.

As all the calculations are made on your local machine, no images are uploaded to the server. Therefore you can use images as big as you like, there are no restrictions. Be aware, there are some issues for the “Lens feature” on Edge and Internet Explorer. All others should support everything just fine.

So go ahead, choose an image through the upload functionality or just drag and drop your image in the center of our Color BLIndness Simulator. It is also possible to zoom and move your images around using your mouse – try it out, I hope you like it.

If there are any issues with the Color BLIndness Simulator please send a note through the contact page. Thanks. If this simulator is not correctly working for you, you could still try the old version which can be found at Coblis.v1 – Color Blindness Simulator.

As it is not not so easy to describe color blindness it comes in handy, that some smart people developed manipulation-algorithms to fake any form of color vision deficiency. The algorithms transform any picture into the same picture as seen by red-, green-, blue- or completely colorblind people.

I would like to thank Michael from ColorJack for providing the color blindness matrix, which was used for the first version of the Color BLIndness Simulator. The actual version ist based on the jsColorblindSimulator-Project developed by MaPePeR. He made it possible to use just client resources and added some very cool features like pan&zoom. At the moment the HCIRN Color Blind Simulation function is used, which is freely available for non-commercial use.

The Color Blind Simulation function is
copyright (c) 2000-2001 by Matthew Wickline and the
Human-Computer Interaction Resource Network ( ).
It is used with the permission of Matthew Wickline and HCIRN,
and is freely available for non-commercial use. For commercial use, please
contact the Human-Computer Interaction Resource Network ( ).