When using an Offline Storage File (OST) in Outlook, you can come across situations that may call for the conversion of an OST file into a Personal Folders File (PST). For this, 5 free methods to convert OST file into PST file format are brought out below.

Free Methods to Convert OST to PST

Method 1 – Use Import and Export Wizard

Note: For this method, it is necessary that your mailbox is connected to the Exchange server and you have Outlook installed on your machine.

To convert OST file to PST by using Outlook Import/Export Wizard, follow the given steps:

  • Step 1: Open your Outlook application and click File.
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  • Step 2: In the window that appears, select Open & Export and then click Import/Export.
  • Step 3: From the Import and Export Wizard, under Choose an action to perform section, select ‘Export to a File’. Click Next to continue.
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  • Step 4: From the ‘Export to a File’ dialog box, choose Outlook Data file (.pst), and click Next.
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  • Step 5: From the Export Outlook Data File dialog box, choose the folder you need to export from, and click on the Next button.
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  • Step 6: Under the Options section, choose any of the provided options and click on the Finish button.
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  • Step 7: On clicking OK when prompted, your OST file will get saved in PST format at the selected location.

Method 2 – Recreate OST File and Convert it into PST

If Outlook is connected to Exchange Server, you can recreate the OST file and then convert it into a PST file. This will allow access to mailbox contents when OST file data becomes damaged or inaccessible.

For recreating an Offline Outlook data file (.ost), you just need to delete the .ost file and it will be recreated the next time you open the Outlook. Once the file is recreated, it can be exported to an Outlook data file (.pst) by following the steps mentioned in the method above.

Note: In case it is not possible to access Outlook due to Outlook account being disabled, synchronization error, or damage of MAPI profile, it may not be possible to recreate the OST file. In that case, the only way to convert OST to PST is to use software such as Stellar Converter for OST.

Also Check: How to Convert Audio or Video Files to Any Format Using VLC

Method 3 – Drag and Drop OST File Items to PST

Dragging and dropping OST file items into a new PST file is another way to perform the conversion. For this, follow these steps:

  • Step 1: Launch Outlook.
  • Step 2: Create a new PST file for your Outlook profile by Click New Items > More Items > Outlook Data File.
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  • Specify PST file name, choose Outlook Data File (*.pst) from ‘Save as type’ drop-down list, and then click OK.

NOTE: If a password-protected PST file is required to be created, click ‘Add Optional Password’.

Method 4 – Use Archive Feature for OST to PST Conversion

In this method, it is required to archive OST mailbox folders to a PST file by following these steps:

NOTE: The archive feature will not work if your Outlook profile is connected to an Exchange Server.

  • Step 1: In Outlook, click File.
  • Step 2: Select Info, click Tools and then click Clean Up Old Items (for users of Outlook 2016 and higher version)
  • Step 2: Select Info > Cleanup Tools > Archive (for users of Outlook 2013)
  • Step 3: Choose Archive this folder and all subfolders option and select the OST mailbox folder to be archived.
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  • Step 4: Enter a date in the drop-down next to Archive items older than.
  • Step 5: Click Browse to select the folder where the archived file is to be saved.
  • Step 6: Specify folder name and click OK. The archived items will be moved to this location
  • Step 7: Click OK to initiate the process.

Once you’re finished with these steps, the selected files and folders will be moved to archive PST.

Drawbacks of Manual Methods

The above-discussed manual methods have certain limitations like:

  • Require original profile used to create OST file.
  • Do not support conversion of inaccessible OST file. 
  • Time taking for converting a large-sized OST file. 
  • No option to preview before the conversion. 
  • Few options for saving converted OST file as a PST file.
  • Prone to errors such as accidental deletion, overwriting of data, etc.

Method 5 – Use OST to PST Converter Software

The limitations of manual methods can be overcome by using the demo version of Stellar Converter for OST software, as it 

  • Does not require the original profile used for generating Offline Storage Folders (.ost) file.
  • Supports conversion of inaccessible OST file to PST format.
  • Converts OST to PST in a few simple clicks: ‘Select OST’, ‘Convert’, ‘Preview & Save as PST’.
  • Performs conversion with precision and maintains data integrity.

Detailed steps to perform OST to PST conversion are as follows:

  • Step 1:  Download, install and launch Stellar Converter for OST software. 
  • Step 2: In the Select OST File for Conversion window, click Browse or Find to select the file to be converted.
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  • Step 3: Once the file is selected, click Convert to initiate the conversion process.
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  • Step 4: The software displays a preview of the converted file. For saving the file, click Save Converted File on Home menu.
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  • Step 5: In the Save As dialog box that appears, select PST under Save As, and then browse the location to save the PST file. Click OK.
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The converted file will get saved at the selected location. 

Note: The demo version of the software allows to convert and save 20 items per folder for free. For saving all the converted OST file items as PST, it is required to activate the licensed version of the software. 

A straightforward UI of Stellar Converter for OST makes the conversion process simple and quick. The tool extracts items from Offline Outlook Data File (.ost) file and saves them in PST format, maintaining the integrity of the mailbox items. For its ease of use and brilliant performance, the software is acknowledged by Microsoft MVPs also.