999 File - opening and understanding

Did your computer fail to open a 999 file? We explain what they are used for and recommend software that we know can open or otherwise handle your .999 files.

What is a 999 file?

The .999 file extension is most commonly used by Sage business software applications. The 999 files contain backup files that have been created with a Sage program.

The .999 file extension is also used for multi-pass security files.

How to open 999 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 999 for different purposes.

While we have not verified the apps ourselves yet, our users have suggested 4 different 999 openers which you will find listed below.

Suggest another file format using extension 999

While we know of one file format using the .999 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 .999 file.

Various viewers for this file format

These apps are known to open certain types of 999 files. Remember, different programs may use 999 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Pro/ENGINEERPro/ENGINEERUser submitted
Creo Elements/ProCreo Elements/ProUser submitted
CreoCreoUser submitted
Pro ENGINEERPro ENGINEERUser submitted
We have not verified any software that we know for certain will work with 999-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 999-files. If you know one, please use the 'Suggest a program' link below and tell us about it!