Everything to Know About Outlook Data Files

Admin | September 14th, 2016 | Apps, Email, Technology

OST File:

If you use MS Outlook with Exchange server then your data like emails, contacts, calendars etc. are saved on the sever and when you enable the MS Outlook to save a local copy as well then it will be saved on your machine as an Offline Storage Table known as OST files with .ost as file extension. This offline storage table will help you view your data even when your Exchange server is not connected or you do not want to connect with it. OST and Exchange are synchronized every time you connect to the server.

Know how to convert your OST files into Outlook PST File?

PST File:

PST (Personal Storage Table) is a data file which allows the user to store the personal contents to their personal folder file. The PST files contain emails, contacts and tasks etc. on the client storage. These folders are stored on the user’s hard drive and are used to create archives or backup of your Outlook folder files. The personal folder files are stored on the Outlook in “.pst” extension. The general users of the personal folder files usually belong to a home group or a small organization group. They use ISP (Internet Service Provider) account protocols like POP3, IMAP and HTTP. All these protocols use “.pst” files.

Difference Between OST and PST Files

  1. OST files are replicas of original file that are stored on user’s computer so that it can be used when server is offline whereas PST files are the original files that are stored on user’s computer so that it can be accessed whenever required.
  2. OST files are cached copy of email folders on the exchange server whereas PST files are original personal contents stored on the user’s hard drive.
  3. OST files can be accessed offline which means it works in the absence of internet connection but PST files requires internet connection.
  4. OST files are synchronized every time when they are connected to the server but in case of PST files it is updated at every instance when user makes any modification to it.
  5. OST files are more stable and less vulnerable to data loss since it is a cached copy of folder files but PST files are secured and still prone to vulnerable data loss due to local data storage.
  6. OST file folders are incompatible and work only with Microsoft exchange server instead PST file folders are compatible and can work with Exchange server.
  7. OST files are found on the server storage whereas PST files are found on the client storage.
  8. OST files can be imported to other accounts as a mailbox whereas PST files can be used as back up so it can be easily moved from one computer to other.


Although OST and PST files but are the MS Outlook data files but vary a lot in terms of their accessibility. An Exchange OST file can be used in your Local MS Outlook but it has to be first converted into PST.