Having problems opening a C21 file?

We have programs that open, view or play your C21 files.

Opening C21 files

Did your computer fail to open a C21 file? We explain what C21 files are and recommend software that we know can open or convert your C21 files.

What is a C21 file?

Every day thousands of users submit information to us about which programs they use to open specific types of files.

While we do not yet have a description of the C21 file format and what it is normally used for, we do know which programs are known to open these files. See the list of programs recommended by our users below.

We are constantly working on adding more file type descriptions to the site - the current count exceeds thousand by far, and more information about C21 files will hopefully be added soon.

Software that will open, convert or fix C21 files

Try a universal file viewer

Try a universal file viewer like Free File Viewer. It can open over 200 different types of files - and most likely yours too. Download Free File Viewer here.

About File Extension C21

File.org aims to be the go-to resource for file type- and related software information. We spend countless hours researching various file formats and software that can open, convert, create or otherwise work with those files.

If you have additional information about the C21 file format or software that uses files with the C21 suffix, please do get in touch - we would love hearing from you.