Stellar Converter for OST

Top Use Cases

When to Use Stellar Converter for OST?

Export OST to PST
Extract Mailbox Data

If you delete a user mailbox from Exchange without backup, the only way to access the mailbox data is through the OST file. However, you cannot recreate or rebuild the OST file if the Exchange user account is deleted from Active Directory. Stellar OST converter tool converts the inaccessible OST file into a PST file, which can be imported into Exchange Server.

Learn More arrow
Manage Data files with Stellar Toolkit for Outlook
Manage Data files with Stellar Toolkit for Outlook

Stellar Toolkit for Outlook provides an 8-in-1 solution for your OST and PST files. The tool easily converts OST into PST and exports mailbox data directly to Office 365 or live Exchange. The other tools help repair corrupted PST files, split or compact PST, merge PST files, remove junk, and much more.

Learn More arrow
Migrate from Hosted Exchange to Microsoft 365
Need to Consolidate

Are you using Hosted Microsoft Exchange service? You don't have access to your email services, not having archive services available, and are not able to restore email services due to a compromised server. You have Outlook data file(.ost) available can restore all mailbox data and move to Office 365/M365. Stellar Converter for OST Technician Edition can convert OST files to Microsoft 365. It retains the original folder hierarchy and performs quick OST to Microsoft 365 migration without causing any data loss.

Learn More arrow

Key Features of Stellar OST to PST Converter

Software Important Capabilities

Converts Large-Sized OST File

Converts Large-Sized OST File

Stellar has rigorously tested its OST to PST converter tool for converting large-sized OST files. The software performs the fastest conversion of large OST into PST. It helps convert OST file when Microsoft Outlook or Exchange Server is crashed or inaccessible or Outlook faces synchronization issues. It converts the OST file into PST and extracts the data with 100% precision.

Is Hosted Exchange Compromised?

Is Hosted Exchange Compromised? New

No Access to your email services due to a Compromised or failed Hosted Exchange Server. Non-availability of archive data, & require to restore email services, only require Outlook data file(.ost), to migrate to Office 365/ M365 or save to PST. Stellar Converter for OST Technician efficiently helps you to migrate Hosted Exchange Server to M365/O365 with 100% precision.
Download Now

Auto-Locates and Lists Outlook Data File

Auto-Locates and Lists Outlook Data File

Stellar OST PST conversion tool auto-locates and lists the OST files from the default location. This allows you to select the OST file quickly, scan it, extract mail items, and save them in desired format. You can also browse and select the OST file manually or use the ‘Find’ option to search and select the OST file for conversion when the location is not known.

Extracts All Offline Outlook Data File (.ost) Items

Extracts All Offline Outlook Data File (.ost) Items

The OST to PST converter by Stellar extracts all the items from OST - emails, attachments, contacts, calendars, tasks, notes, journals, etc. The tool performs precise OST 2 PST conversion and maintains the original integrity of mailbox items. It is the best solution for any situation requiring the user to move the OST file to PST and convert OST to PST without an Exchange profile. 
Learn More


Reviews & Feedback

Recommendation by Microsoft MVPs

Edward van Biljon(MVP, Microsoft Community Contributor)
Nuno MotaSenior Exchange and Office 365 Consultant
Daniel BeatoSystem Administrator

Other Important Features

Know your Product Better

Free Preview of Offline Outlook Data file

Free Preview of Offline Outlook Data file

The software displays a detailed preview of the mailbox items stored in the converted OST file. The user can click a folder, email, calendar, or other mailbox items listed in the Preview pane to view its contents. The Preview feature helps identify and extract specific items from the offline Outlook data file (OST).

Sorts and Organizes the Messages

Sorts and Organizes the Messages

The OST PST converter software extracts OST file data in an organized manner while maintaining the original arrangement of mail items. Once the OST scanning is completed, the software allows sorting and organizing of emails by Date, From, To, Subject, Type, Attachment, Importance, etc.
Learn More

Find and Save Individual Mail Items

Find and Save Individual Mail Items

You can use the Find Message button to open the Find Message window and search specific emails or mail items based on various parameters, such as ‘To,’ ‘From,’ ‘Subject,’ ‘Message text,’ etc. You can then right-click on the email to save it in PST, MSG, EML, RTF, HTML, or PDF file format at your desired location.

Allows to Save and Load the Scanned File

Allows to Save and Load the Scanned File

The OST PST converter tool allows the user to save the OST file 'scan' information as a DAT file to load it later for the conversion. This feature helps split the OST to PST conversion process into two stages, doable at different times or on different systems.
Learn More

Auto-Split Large PST Files

Auto-Split Large PST Files

The OST to PST converter software features an Auto-Split option that automatically splits an oversized or large PST file at approximately 45 GB while saving the converted mail items from OST files. This helps prevent PST file corruption due to its large size.

Exports the OST Data to Office 365

Exports the OST Data to Office 365

The software can directly export the OST to PST converted files to Office 365. It allows the user to log in to an Office 365 account and exports the mailboxes directly through its interface. The OST to Office 365 Export feature is available in the Technician Edition of the software.

Converts OST into Multiple File Formats

Converts OST into Multiple File Formats

The OST to PST conversion tool allows the user to extract the mailbox data in different file formats, such as PST, MSG, EML, RTF, HTML, and PDF. In addition, this allows the user to view the OST file contents in applications, such as Outlook, web browser, PDF reader, text reader, etc.
Learn More

Converts Multiple OST Files in a Batch

Converts Multiple OST Files in a Batch

The tool can convert multiple OST files into PSTs through a single batch process. The Batch Conversion feature is helpful when an organization is moving to a new email service and needs to extract mailbox data from several OST files. The Batch Conversion feature is available in Technician Edition.

Free OST to PST Conversion

Free OST to PST Conversion

The tool allows free OST file to PST file conversion and extracts 20 emails per folder. Use this free OST to PST converter to scan the OST file. After scanning the Outlook OST file, preview the converted OST file and save the mail items in a PST (Personal Storage Table) by clicking the 'Save converted file' button.

Splits Large-Sized PST File

Splits Large-Sized PST File

In addition to auto-split based on size, the Technician edition of the software also provides option to split the PST file in the sizes of 1-50 GB while preserving the original organization of the mailbox data. The feature helps in managing the large PST files.
Learn More

Compacts PST File

Compacts PST File

The Technician edition of the software offers a Compact PST file option, allowing you to compress large PST files. The option also helps you extract and save the attachments from PST file in a separate folder while preserving interlinks through the PST file. You can also use this option to save all attachments in new PST file.
Learn More

Conversion of Encrypted OST File

Conversion of Encrypted OST File

A user may face an error when trying to open an encrypted OST file, leading to loss of access to the mailbox data. Converting the encrypted OST file into PST (Personal Storage Table) file can solve this problem. Stellar's OST to PST converter converts the encrypted OST into PST, thus allowing access to the mailbox data.
Learn More

How to Use Stellar Converter for OST

Screenshots & Video


Choose as per your need


Convert OST to PST and extract all mailbox items



SAVE $20
  • Converts OST into PST format
  • Lists all OST files from the default location
  • Converts All Offline Mailbox items with Free Preview
  • Saves & loads scan data
  • Auto-splits large PST files while saving the mail items
  • Advanced filter options for precise conversion
  • Saves the mailbox data in PST, EML, MSG, RTF, HTML, and PDF file formats

Convert multiple OST files and export to Exchange or Microsoft 365



SAVE $50
  • Includes all features of Corporate
  • Converts multiple OST files in batch
  • Compacts & Splits PST file
  • Exports to live Exchange
  • Migrate to Microsoft 365
  • Exports to MS Outlook
  • Exports contacts in CSV file

Read More

Best Seller

All features of Technician + 7 more tools



SAVE $300
  • Includes all features of Technician
  • Repairs corrupted PST file
  • Recovers the mailbox items
  • Merges multiple PST files
  • Removes duplicate emails
  • Recovers lost password of PST
  • Restores the deleted emails

Read More


All The Information You Need


You're in Good Hands


Most tested. Most awarded. For over 30 years, we’ve been recognized as experts

q1 q1
ExpertExchange star

Stellar Converter for OST saves your business & time

With its great features, Good Interface, and ease of using Stellar OST to PST deserves 10 out of 10.

MakeUseOf star

Convert OST files to PST easily

Stellar Converter for OST makes OST to PST conversion process hassle-free

SpiceWorks star

Awesome OST TO PST Software

Stellar OST to PST converter has worked wonders for Outlook 2003 to 2016 conversions of OST Files. This application I use and resort to. star

Helps admin to easily convert any OST file to PST

It converts an entire OST file, or items within an OST file, into a PST without changing the original content format or structuring.

TweakTown star

Powerful OST to PST Converter Tool

Stellar Converter for OST converted all items from OST file to PST with complete integrity & precision.


Technical Specifications

product Icon
About Product
Stellar Converter for OST
License: Single User
Edition: Corporate, Technician, & Toolkit
Language Supported: English, Deutsch, Français, Italiano, Español, 日本語
Release Date: October, 2022
System Requirement
Processor: Intel-compatible (x86, x64)
Memory: 4 GB minimum (8 GB recommended)
Hard Disk: 250 MB for installation files
Operating System: Windows 11, 10, 8.1, 8, 7


Product Related Articles


Free Trial Download

  • No File Size Limitations
  • Trusted by Millions of Users
  • Awarded by Top Tech Media
  • 100% Safe & Secure to Use

*Free Download enables you to preview the converted file and save 20 items per folder.



Follow these steps to convert an OST file into PST file by using the software:

  1. Run Stellar Converter for OST
  2. Browse and select the Offline Outlook Data File (.ost)
  3. Click 'Convert' button to start the conversion process
  4. Click 'Save Converted File' button to save the mailbox data
  5. Select Outlook Data File (.pst) as the file format to save the converted data in PST file
  6. Click ‘Browse’ to specify the location and click ‘OK’ to save the data

The software will scan the OST file & list all the items preview in a tree-structure view. Verify the data and save them at your destination location.

The OST to PST Conversion Software is best option to migrate Hosted Exchange mailboxes to Microsoft 365.

  1. Run Stellar Converter for OST Technician Edition
  2. Select the Offline Outlook Data File (.ost)
  3. Click 'Convert' to start conversion process
  4. Click on 'Save Converted File' button to save OST file
  5. Select 'Export to Microsoft 365' and click on 'Next' button
  6. Enter Office 365 or Microsoft 365 credentials and click OK.
  7. This will export the OST file to Microsoft 365 mailbox directly

Stellar Converter for OST Technician Edition will scan the OST file and list all the mailbox folders in the left pane. Click on a folder to preview its items and migrate them directly to Microsoft 365. Download Now

  1. Launch Microsoft Outlook.
  2. Open File tab.
  3. Click on ‘Open & Export’
  4. Now Select Import/Export option.
  5. Click on ‘Import from another file or file’.
  6. Click on ‘Next’ button.
  7. Select Outlook Data File (.pst)
  8. Click on the Next button.
  9. Browse the file to import & Click on the ‘Next’
  10. Choose Finish.

Now Microsoft Outlook will start importing the items of your Outlook Data File (.pst) immediately.

The Demo version of the software converts the Outlook OST file and previews the complete mailbox data. It also allows you to extract and save up to 20 items per folder.

Yes, Stellar Converter for OST allows you to search for the OST files (Offline Storage Table) stored in any folder, sub-folder, or drive in your system. Use 'Find Outlook File' feature of the software to locate the OST files.

You would need to convert an OST file into PST file in any of the following cases:

  • You need to access the emails from a mailbox that is deleted from Exchange
  • You are facing issues while synchronizing Outlook with Exchange Server
  • You need to migrate the email organization to a different platform
  • You need to recreate or rebuild the OST file in case of an Exchange Server crash/disaster
  • You are facing difficulty with Outlook Import/Export Wizard
  • You need to change the location of the offline Outlook Data File (.ost) in Microsoft Outlook
  • You need to move Outlook OST file to another disk

Or facing an error while accessing OST file –

  • Outlook is using an old copy of your Offline Folder File (.ost). Exit Outlook and delete the .ost file, and restart Outlook.
  • errors have been detected in the file outlook ost
  • outlook cannot configure OST file

The total time for converting an OST file into a PST file depends upon the OST file size. Stellar Converter for OST takes approx. Seven minutes to convert per GB of OST file into PST.

The software can save the converted OST file into MSG, EML, PDF, RTF, or HTML file formats.

If you face any problem during or after an OST file conversion, you can contact the Stellar support team:

The software is available in two variants – Corporate & Technician. If you only need to convert an OST file into PST file, then you should go for Corporate. If you want to convert and also compact or split a PST file, then you should use the Technician edition. The Technician edition can also export the OST file data to Office 365.

Stellar Converter for OST is available in three different editions: Corporate, Technician, and Toolkit. The Corporate edition is available with a single-device license and can be installed only on a single device or system. The Stellar Converter for OST - Technician and Toolkit editions are available with a Bulk Licensing option. If you choose Technician or Toolkit edition, you can purchase licenses based on the number of devices or systems you have. At a time, you can purchase bulk licenses for Technician and Toolkit editions for 1, 5, 10, 25, 50, 100, 200, or 500 devices or systems. Read More

Yes, the software converts OST file that is not connected to Exchange Server.

Yes, the software guarantees OST to PST file conversion; however, we strongly recommend trying the free Demo version of the software which previews the mailbox data stored in OST and also converts up to 20 mailbox items per folder. After ascertaining the software effectiveness, you can activate it with a license key and then convert & save all mailbox items in PST or other file formats.

Yes, you can open the converted OST on another system after saving the OST file in a format such as PST, EML, RTF, or other supported file formats.

The software does not perform any action on the corrupted OST file. It converts the corrupt OST file in PST file, thus enabling access to the OST file data.


Why Choose Stellar?

  • 0M+


  • 0+

    Years of Excellence

  • 0+

    R&D Engineers

  • 0+


  • 0+


  • 0+

    Awards Received