File Type Generic IconBackup File
File Format Standard
Usage Referenced by an application; not meant to be opened manually; may run a program or script when opened
Popularity ★ ★ ★ ★ ☆  Common

The ".old" extension is typically appended to a backup copy of a file. For example, before an important file is updated, a user may duplicate the file and add the ".old" extension to the copy. This indicates it is the "old" version of the file. If the updated file becomes unusable, the old version can be used to restore the file.

IMPORTANT: In order for the backup file to work correctly, the ".old" extension may need to be removed from the filename.

Open With

IconOriginal program


IconOriginal program

Updated June 1, 2009
Information from the PC File Extensions Reference