PST File Extension

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

What is the .PST file type?

The .pst extension is associated with the 'Personal Storage Table' (PST) proprietary file format and file type used by Microsoft (MS) Outlook, a messaging part of MS Office. MS Outlook would use a single PST file to store all user data within a particular POP3/IMAP/web-mail account, including folders, messages, attachments, calendar events, tasks etc.

A PST file functions like a database container with its internal indexing for faster access. Like with mailbox file types, any deleted messages are not instantly removed from a PST file and can be recovered until the PST file is compacted. PST can be protected with a password and/or encrypted.

In Windows Vista/7/8, user PST files are stored in the '\Users\user\AppData\Local\Microsoft\Outlook' directory by default. It is possible to define a custom path to store PST files, even on a removable volume.

In versions prior to MS Outlook 2003, size of any .pst file was limited to 2 Gb, which was known to cause severe performance and stability issues. In subsequent versions, the size limit is 20 Gb/file.

Software to open or convert PST files

You can open PST files with the following programs: 

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