COS File - opening and understanding

Did your computer fail to open a COS file? We explain what they are used for and recommend software that we know can open or otherwise handle your .COS files.

What is a COS file?

A .COS file is a WinArcadia Saved State file. Through our analysis of COS files, we know that one use of the format is WinArcadia Saved State. We have not yet described in detail what these files contain and what they are used for, but our team is working tiredlessly through thousands of file formats. We'd love hearing from you if you have information about the format.

How to open COS files

You will need a program compatible with the specific file you are trying to open, as different programs may use files with file extension COS for different purposes.

While we have not verified the apps ourselves yet, our users have suggested 4 different COS openers which you will find listed below.

Suggest another file format using extension COS

While we know of one file format using the .COS file extension, there may be more. It is widespread that different programs use files with the same file extension for very different types of data. Please let us know if you are aware of a different kind of .COS file.

Various viewers for this file format

These apps are known to open certain types of COS files. Remember, different programs may use COS files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Command OpsCommand OpsUser submitted
Scenario MakerScenario MakerUser submitted
Cot Cot CothelloCot Cot CothelloUser submitted
ComptanooComptanooUser submitted
We have not verified any software that we know for certain will work with COS-files on Mac. If you know one, please use the 'Suggest a program' link below and tell us about it!
We have not verified any web services that we know for certain will work with COS-files. If you know one, please use the 'Suggest a program' link below and tell us about it!