Filename Extensions
If you are seeking information about file extensions, then you are in the right place at right time.

Details of extension .ost

1 extension(s) and 0 alias(es) in our database

Below, you can find answers to the following questions:

  • What is the .ost file?
  • Which program can create the .ost file?
  • Where can you find a description of the .ost format?
  • What can convert .ost files to a different format?
  • Which MIME-type is associated with the .ost extension?
Microsoft Outlook Offline Folder File .ost file icon

Microsoft Outlook Offline Folder File

The OST file is a Microsoft Outlook Offline Folder File.
Detailed description not available
Category: Data files
Application: Microsoft Outlook
Program name: -
Mime-type: application/octet-stream
Magic bytes (HEX): -
Magic string (ASCII): -
Related extensions:
Microsoft Outlook Navigation Bar
Microsoft Outlook Template
Microsoft Outlook Profile
Microsoft Outlook Personal Folder File
Microsoft Outlook Form Storage
Microsoft Outlook Rules Wizard Data
Microsoft Outlook Personal Address Book
Microsoft Outlook 2000 Auto Complete Nick List
Microsoft Outlook 2002 Auto Complete Nick List

Other types of files may also use the .ost file extension. If you have helpful information about .ost extension, write to us!

Is it possible that the filename extension is misspelled?

We found the following similar extensions in our database:

IsoStar Library of Intermolecular Interactions Data
Olivetti Olitext Plus Script
IAR System List Output Data
Radiance Octree
eSignal Order Entry Ticket Data
ObjectScript Source Code
Descent 3 Outrage Sound
OpenSceneGraph Scene
IBM InfoSphere Schema Data

The .ost filename extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

owt (1), ot (1), osh (1), osf (1), oet (1), lst (1), st (1), ist (1), pst (1), oxt (1), ots (1), osr (1), osg (1), os (1), oct (1)

Can't open a .ost file?

If you want to open a .ost file on your computer, you just need to have the appropriate program installed. If the .ost association isn't set correctly, you may receive the following error message:

Windows can't open this file:

File: example.ost

To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select from a list of programs that are installed on your computer.

To change file associations:

  • Right-click a file with the extension whose association you want to change, and then click Open With.
  • In the Open With dialog box, click the program whith which you want the file to open, or click Browse to locate the program that you want.
  • Select the Always use the selected program to open this kind of file check box.

Supported operating systems

Windows Server 2003/2008/2012/2016, Windows 7, Windows 8, Windows 10, Linux, FreeBSD, NetBSD, OpenBSD, Mac OS X, iOS, Android