Free Methods to Convert OST to PST in Outlook 2019/ 2016/ 2013/ 2010/2007

Updated on January 11th, 2022

Kuljeet Singh

Summary: The blog summarizes the best ways to convert Exchange OST mailboxes to Microsoft Outlook PST file format. It also describes the benefits and drawbacks associated with each of these OST to PST export approaches and suggests the recommended conversion method towards the end.

(Offline Storage Tables) OSTs provide an efficient medium to access Exchange Server mailbox folders locally on the Outlook client when reliable internet connectivity is not available. It allows continuing with the Outlook mailbox functionality in the offline mode i.e., without connecting to the Server. Though OST files cannot be affected easily by outer disturbances, there are several reasons that make OST data inaccessible and affects the routine business operations.

MVP’s Advice: Try Stellar Converter for OST to convert a single/multiple Exchange OST files into Outlook PST smoothly.  Compatible with  Office 365 & all MS Outlook versions: Outlook 2019, 2016, 2013, 2010, 2007, 2003, 2002, and 2000.

Regardless of the Outlook version, whether it is Microsoft Outlook 2019, 2016, 2013, 2010, 2007 or any older ANSI edition, inaccessible OST file requires troubleshooting in order to regain access to the data stored within. The easiest way to fix all types of OST issues, irrespective of the extent of damage or loss is to convert the OST file to Outlook PST file.

There are several ways to migrate OST data to PST format, but every user would want to know the safest way to migrate OST file data to PST and what are the recommendations of Outlook MVPs & Administrators. To begin with, here are a few snippets taken from technology forums:

Lasse Pettersson (Exchange MVP and MCSM messaging):

Diane Poremsky MVP ( (Outlook MVP)

Karl Timmermans (Outlook MVP)

Hal Hostetler (Outlook MVP)

Key facts to consider before OST file conversion

  • You cannot extract data from OST file to a PST directly. That means, you need to be logged in with the original profile in order to export the OST file data to PST. For this, use methods 1, 3, and 4 below.
  • OST files are a local copy of your mailbox, you can recreate it by resyncing with the mailbox.
  • There is no way to convert an OST file to a PST file by using Microsoft tools if your original email account is not available or if your OST file is corrupt. In this case, there’s only one way you can convert the OST file to PST— by using a specialized OST converter software. See method 2 below.

Method#1: Use Outlook Archive feature

Use the Archive feature in Outlook to copy or move mailbox items to PST. It converts all the items of OST mailbox to PST format. This feature does not allow archiving Contacts; however, all other mailbox items can be moved. Follow the steps below:

1. Open MS Outlook and then open the OST file from which the data needs to be exported
2. Click on File tab, click on Info, and then click on CleanUp Tools
3. Next, select Archive from the options
4. In the Archive dialog box that appears, ensure that Archive this folder and all subfolders option is selected (it is selected by default)
5. Next, select the folder that you need to export to PST (e.g.: Inbox)
6. In the Archive items older than: box, provide an appropriate date. All the items that were received earlier till the specified date will be archived
7. Under Archive file: option, provide the destination path to store the new PST
8. Click on OK to accomplish the export process

Method#2: Stellar Converter for OST

The professional OST to PST Converter tool provides an automatic utility to export multiple OST files to Outlook PSTs, and extract all the mailbox data intact. The tool also splits and compacts the PST files to help you manage them in a more organized manner. In addition to this, it also directly migrates (exports) the OST file data to Office 365, which immensely helps in case you’re migrating your mailboxes to cloud. For these reasons, the software-based OST conversion method is recommended by Microsoft MVPs.

You can also check Software Video Tutorial

The tool also converts encrypted OST files to extract all the mailbox data in PST files. The security and integrity of mailbox items are maintained as well as the folder structures are taken care of during the export process. The tool is easy-to-use and caters to all types on need. Follow the steps below:

1. Download and Install OST to PST Converter tool  


2. Click on Browse button to upload the OST file to the tool’s panel



3. If you do not know the exact location of the OST file, click on Find button
4. Once the OST file is uploaded, click on the Convert button to begin the scanning process

convert ost file to pst file

Note: The overall time that the tool takes to scan a file depends upon the volume of data it incorporates. You can also abort the scan process by clicking on the Stop button.

5. In the dialog box that appears, select the PST option under Save As section. Under the Destination Path section, click on Browse to provide the storage location for saving the resultant PST file.

free ost to pst converter in outlook 2016

Other than saving Exchange OST mailboxes to Outlook PST file, the software allows converting the Offline files to multiple file formats including MSG, HTML, EML, PDF, and RTF. These files can be accessed on desktop-based and web-based email client on both Windows and Mac operating systems.

Method#3: Drag and Drop Mailbox Items

Dragging and dropping OST mailbox items to PST file format is, undoubtedly, the best way to migrate data from OST to PST. To accomplish this, you will need to make a blank PST file in MS Outlook and then click and drag the desired items from OST mailbox to a newly created PST file.

However, there are some limitations associated with the drag and drop mailbox items procedure. Firstly, you will need to repeat the process for every individual item that needs to be moved to the PST mailbox. This requires attention to detail as the process is time-consuming; therefore, a single mistake will lead to an unnecessary repetition of the process.

Moreover, the folder structure, as well as the default folders such as Calendars, Contacts, Inbox, etc., cannot be directly migrated and you need to create a new PST file to manage the entire data in an organized manner.

Method#4: Outlook Import & Export Wizard

Microsoft Outlook Import and Export wizard is an effective way to convert OST data to PST file format in Outlook 2010 and other versions. You can also migrate OST data to Excel and CSV file formats by using this method. However, you would need to be careful while executing the steps as this is a manual method.

Also, you need to be technically proficient to implement the built-in import/export strategy. Any mistake may result in loss of access to your valuable data So, it is recommended to back up the OST file before starting the export process so that you can restore the data if the need be.


Some users believe that manual methods are difficult and may result in data loss. But, the fact is, it totally depends on your specific situation. For instance, if you have the necessary technical skills and your Outlook account is available, then you can safely choose manual methods like – Outlook Archive feature, Import-Export Wizard, or Drag and Drop Mailbox Items to migrate OST file to PST. But, you would anyway need to spend more time due to repeat execution of manual steps, close manual checks on the procedures, and dedicated manpower utilization.

But, if the associated Outlook profile is not available and your OST file is corrupt, then it’s more convenient (and safer) to export OST file data by using a professional OST to PST converter software such as Stellar Converter for OST Software, we outlined in this post. Plus, it frees you of the need to do constant task monitoring and manpower use, and is faster because tasks can be selected and run in batches. Overall, the software’s value lies in offering you execution speed, DIY convenience, and more cutting-edge features for tough cases like encryption.

Check out Stellar Converter for OST MVP reviews here.

About The Author

Eric Simson

Eric Simson is an Email Platform Consultant and is associated with Stellar Data Recovery from last 6 years. He writes about the latest technology tips and provides custom solutions related to MS Outlook, MS Exchange Server, Office 365, and many other Email Clients & Servers. 

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  1. I am using this tool from the last 5 years without any error. Now, I also support the latest Outlook 2019 build.


  2. Thanks for sharing this automatic solution without any technical knowledge. Now, we can do this conversion without any technical knowledge.

  3. To convert OST to PST, I personally recommend using stellar OST to PST Converter that is freely available and ads-free also. Unlike other tools, it works even if you do not have an Exchange Server connection.

    So, you can easily recover Exchange mailbox folders by converting OST to PST and opening the converted PST file in Outlook.

  4. Yesterday, I had noticed that my archive Outlook folder (OST) was inaccessible. Right now, our company is planning to upload to Office 365. But, our concern is corrupt OST file.

    Is it possible to repair OST file using this software?

  5. Hi Erick,

    If you don’t mind, I want to share my feedback with others.

    According to my observation, the manual method is not a safe choice for non-technical users.

    I also prefer third party software to avoid any kind of mess with client’s data.

    Sr. Project Manager
    Office & Exchange Tech Services

    1. Hi Nicholas,

      Thanks for your advice!

      We also agree that automated solution is safe & secure. In the manual method, a single mistake can lead towards a bad experience of data loss.

  6. Personally, I can suggest that the manual method is useful for tech background users only. For a non-technical user, the automated software is a good and safe choice.

    1. Our software uses an advanced algorithm to detect any version of MS Outlook OST file.Apart from the conversion, it also reconstructs the damaged blocks in OST file.

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