How to open P21 files

Did your computer fail to open a P21 file? We explain what P21 files are and recommend software that we know can open or convert your P21 files.

What is a P21 file?

The P21 file extension indicates to your device which app can open the file. However, different programs may use the P21 file type for different types of data.

While we do not yet describe the P21 file format and its common uses, we do know which programs are known to open these files, as we receive dozens of suggestions from users like yourself every day about specific file types and which programs they use to open them.

We are continually working on adding more file type descriptions to the site, so if you have information about P21 files that you think will help others, please use the Update Info link below to submit it to us - we'd love to hear from you!

Generic P21

These apps are known to open certain types of P21 files. Since many different programs may use P21 files for different purposes, you may need to try a few of the apps to open your specific P21 file.

QuickParQuickParUser submitted
SmartParSmartParUser submitted
Jw_cadJw_cadUser submitted
Autodesk SXF ViewerAutodesk SXF ViewerUser submitted
AR_CADAR_CADUser submitted
IDA-STEPIDA-STEPUser submitted
MUSASHIMUSASHIUser submitted
it'sCAD MAXit'sCAD MAXUser submitted
DynaCADDynaCADUser submitted
FILDER RiseSFILDER RiseSUser submitted

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.

We have not verified any programs that we know for certain can work with P21-files on Mac. If you know one, please use the Suggest link below and tell us about it!
We have not verified any online services that we know for certain can work with P21-files. If you know one, please use the Suggest link below and tell us about it!