3 File Extension

Have a problem opening a .3 file? We collect information about file formats and can explain what 3 files are. Additionally we recommend software suitable for opening or converting such files.

What is the .3 file type?

Similar to other one-digit numerical extensions, the .3 extension is primarily used as a version indicator for document-type files of different formats. The .3 suffix would normally be appended to the existing file's extension to indicate that this is the third version of the file. The .3 extension does not define either specific file type or file format, it simply points out to the file's current version.

As an example of the above, the .3 extension is used with Pro/Engineer, a highly complex and powerful CAD suite for mechanical and machine engineering. In this context, the .3 extension denotes a particular case of the Pro/Engineer Versioned File file type.

Each time a Pro/Engineer project is saved, the software would preserve the previous version and save the entire changed document into a different file with the respective version index appended (.3 for the third version).

Differently, the .3 and other single-digit extensions can be used to identify a file's position in a chronologically or otherwise ordered sequence. For example, old system log files would be assigned numerical indexes, with the oldest log file having the highest index.

Similarly to the .001, .002 extensions, single-digit extensions like .1, .2, .3 etc. can be also used to identify ordered chunks of a chunk-split file. Such chunks must be rejoined in a proper order before the file can be used as a whole.

Software to open or convert 3 files

You can open 3 files with the following programs:
VLC media player
VLC media player by VideoLAN
3D-Tool by 3D-Tool GmbH & Co. KG
Notepad++ by Notepad++ Team

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