Click the "Select File" button above, and choose your OST file.
You’ll see a preview, if available.
Click the "Convert file to..." button to extract text information.
Convert OST to another file type
To convert OST data files to another format, you need Microsoft Outlook or other Database software.
Convert a file to OST
To convert other file formats to the "Email Storage File" file type, you need software like Microsoft Outlook or a similar tool.
About OST files
A .OST file (Offline Storage Table) is a synchronized local cache of mailbox data used by Microsoft Outlook. It stores emails, contacts, calendar events, and tasks from Exchange, Microsoft 365, or IMAP servers on your local drive. The major disadvantage of the .OST format is its strict dependency on the original Outlook profile and server authentication. If the server crashes, the account gets deleted, or you move the file to another PC, the .OST file becomes an orphaned, inaccessible block of data. It is a proprietary, locked container that cannot be directly opened or imported into a new Outlook client. To recover or migrate your data, you must convert the file. Convert to PST for seamless importing into another Outlook profile. For archiving or sharing individual emails, convert to EML or MSG. For cross-platform reading and permanent legal archiving, convert to PDF.
Convert.Guru analyzes your OST file, detects the exact format, and lets you read the text inside.
If you want to convert OST file to PST, PDF, TMP, TEMP, CACHE, LOG, BAK, OLD, NEW, PART, DOWNLOAD or CRDOWNLOAD, you can use Microsoft Outlook or similar software from the "Local Mailbox Data Cache" category. In the File menu, look for Save As… or Export….
To convert DEVICE, CACHE, SOCK, SYMLINK, PID, MOUNT, FIFO, LOG, PIPE, TMP, JUNCTION or TEMP files to OST, try Microsoft Outlook or another comparable tool in the "Local Mailbox Data Cache" category.
The OST Converter Story
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our OST converter.