1 File - opening and understanding

Did your computer fail to open a 1 file? We explain what they are used for and recommend software that we know can open or otherwise handle your .1 files.

What is a 1 file?

The .1 file extension is used by a variety of computer applications. It is commonly used by the File Splitter software to assign a number to a volume of a split file. This happens when a large archive file is created and the user wants to split the archive file down into smaller volumes. The .1 file extension is given to the first file of the split file archive.

The .1 file extension is also used by the Unix operating system when the system creates an unformatted manual page. In some cases Mozilla Firefox will also use the .1 extension, giving it to files that store data about cookie, image and pop-up permissions. AIM Messenger also uses the .1 extension for certain IM files.

How to open 1 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 1 for different purposes.

While we have not verified the apps ourselves yet, our users have suggested 10 different 1 openers which you will find listed below.

Suggest another file format using extension 1

While we know of one file format using the .1 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 .1 file.

Various viewers for this file format

These apps are known to open certain types of 1 files. Remember, different programs may use 1 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

WinRARWinRARUser submitted
Free File ViewerFree File ViewerUser submitted
Final Media PlayerFinal Media PlayerUser submitted
Pro/ENGINEERPro/ENGINEERUser submitted
DxDesignerDxDesignerUser submitted
Adobe PhotoshopAdobe PhotoshopUser submitted
Snes9X SNES EmulatorSnes9X SNES EmulatorUser submitted
Stuffit ExpanderStuffit ExpanderUser submitted
Microsoft OfficeMicrosoft OfficeUser submitted
Adobe AcrobatAdobe AcrobatUser submitted
We have not verified any software that we know for certain will work with 1-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 1-files. If you know one, please use the 'Suggest a program' link below and tell us about it!