How to Convert Exchange OST to PST in Outlook?

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  • Published on
    December 16th, 2022
  • Updated on
    April 20, 2023
  • Read Time
    14 minutes
4.5/5 - (17 votes)
Summary:- When a user works in an offline mode and his cached mode is enabled then all the data are stored in an OST File. But you can neither import OST to Outlook nor open it unless you convert it to PST. Therefore, we are going to discuss three simple solutions to convert OST to PST in Outlook. These tricks are so effective that you can convert 50 GBs or 60 GBs OST Files to PST. We would discuss the difference between OST to PST, how OST files are created and of course, the steps to convert an offline OST file to an online PST.

OST vs PST – Detailed Comparison of Both File Formats

Let’s begin with the differences between an OST file and PST File. Check out all the differences before you start the conversion process. See, how a PST File is different from an OST file and why you need to convert OST to PST.

Basis of Difference OST File PST File
Meaning MS Outlook stores Offline Outlook Data File ( or OST) format for synchronization with Exchange Server. It contains the essential data that you can easily access online and offline too. Personal Storage Table( or PST) contains your email messages and other Outlook items and saves them on your computer system. It helps to move or copy emails, attachments, and other items from your Mail server account to your computer.
Internet Connectivity When you made any changes in MS Outlook then OST File automatically synchronises the changes and doesn’t need an internet connection. When you manage MS Outlook, the PST File needs an internet connection to make changes in the PST File.
File Compatibility OST Files are only compatible with the Exchange Server. PST Files are compatible with both Exchange Server and MS Outlook.
IMAP and Mapi Emails and Appointments All Emails and Appointments in IMAP and MAPI Accounts are stored in OST from Outlook 2016. Earlier in Outlook 2013, all emails and appointments in IMAP and MAPI Accounts were stored in a PST file format.
In-Built Tool Used to Fix Minor Corruption ScanOST.exe Tool is used to fix minor corruption of OST Files. ScanPST.exe or Inbox Repair Tool is used to fix minor corruption of PST Files.
Automated Tool used to Repair OST and PST File OST Recovery Tool PST Recovery Tool


Need to Convert OST to PST Format

After exploring the difference between these two files, you can analyze yourself they both are totally different. Therefore there are some needs due to which people convert OST to PST.

  • Sudden Exchange Server Crash: You may face an Exchange server crash due to power supply failure, corrupt software, etc. Once your server crashes, you may be unable to connect to the MS Exchange server.
  • Pop-ups OST Files Errors: As we all know, the mailboxes that store various data items in OST files, work after synchronization with MS Exchange Server. Unfortunately, due to some issues, OST files may get corrupt and the error message starts popping up on your screen to notify you that your OST files are not accessible. So, to open and view the corrupt OST mail items, you require to convert OST files to PST format.
  • Job Switching: When users left their old employer, they try to forward all the OST files to another account. But, they forget to realize that their all files are synced with Microsoft Exchange Server and can’t be accessed from another account. To access the OST files on another account, firstly you need to export the OST file to Outlook PST format, and then only you can view it.
  • Corruption of OST Files: MS Outlook offers a facility in OST files that can be viewed and edited online as well as offline. But sometimes, Offline OST files may get corrupted due to abnormal termination, server breakdown, lack of storage space, etc. Therefore OST Files have to be converted to PST.

Free Ways to Convert OST Files to PST in Outlook

I’ll discuss the various methods of OST to PST conversion, which will help you upload all offline OST files’ offline data into your Outlook account. It will hardly take 5 to 10 minutes to convert OST to PST.

Technique #1- Convert Offline OST Mailbox to PST

Note*- You can only import the OST File data to the PST of that Outlook account that is logged and you have created a new PST File to which OST data has to be imported.
Suppose you have an account added to your Outlook and you want the OST file of this account to be converted to the new PST then it is possible with the help of the following method. But if in case you have a copy of the OST file saved separately on your hard drive or PC then it can’t be imported to your Outlook account unless and until it is converted to PST and you will need OST to PST Converter Software.

First, you must log in to your Outlook account using the exchange server from where the OST files have been created and export OST to PST through the following:-

  • Go to the File tab click on the Open & Export option and then click on the Import/Export option.
  • Now, Click on the Export to a File option and then click on the Next Button to Continue.Convert OST to PST
  • Then you will see two options in which you will have to choose the Outlook Data File (.pst) option and then click on Next.
  • Now Select any Folder(s) or the whole Account which you want to import to the New PST file and then click on Next.
  • Now, you should Browse the Location where you have the new PST Files. Then select the appropriate option for Removing or Adding Duplicates items.
  • Click on the Finish Button and your OST File data of the Outlook Account will convert to the new PST file.

Technique #2- Convert OST to PST without using MS Outlook

The only possible way to save OST as PST in Outlook 2019, 2016, and 2013 without an exchange server account is OST to PST Converter. This is a professional tool and has a lot of features that allow you to export OST files to PST within 5 minutes and also help you to convert OST to PST without losing a single data from the file. Additionally, this software will overcome all the drawbacks of the manual method and perform the OST to PST conversion with ease. Some of the multifunctional features of this tool are:-

  • Converts OST to PST file without Outlook
  • There is no need for the same Profile and IMAP Configuration.
  • There is no limitation on the file size of OST that you are converting to PST.
  • Converts a separate OST file saved on your local machine, PC, Laptop, or hard drive.

Why OST to PST Converter has an Upper Hand Over Manual Methods

We are advising you to convert an OST File to PST through a professional tool because the manual method will consume a lot of time and you will be technical expertise to implement it. Therefore, the automated software will just add the OST file and displays all the emails, you will have to choose your desired emails, and in the end, convert OST File to PST. Here you can check out the steps to convert and export OST file emails to PST.

Steps to Convert OST File to PST File using an Automated Tool

  • Download and Launch OST to PST Converter.

First, you will have to download the program to convert OST to PST.

Convert OST to PST

  • Then Add OST file to Convert to PST.

Click on the Select Files button and then Browse the OST file you want to Convert.

  • Preview OST Mailbox Items

The Scanning Process will start and now you will be able to view all the Mailbox items of the OST file.

Convert OST to PST

  • Choose OST Mailboxes

Then Select the Mailbox Items which you want to convert to PST and then click on Save Button.

  • Define Converted OST Location

Choose the location where you want to save the OST files as PST.

  • OST to PST Conversion Confirmation

After the completion of the saving process, you’ll receive a Confirmation Message.

Convert OST to PST

  • Finally, you have converted all Mailbox items of an OST file to PST.

Technique #3- Move OST Mailbox through Archiving

You can try this method as well to import all the mailboxes and folders from an OST file to PST. You will just have to follow the steps given below:-

  • Launch MS Outlook>>File>>Archive.
  • Select the folders that you want to Archive.
  • Browse the location and click on Finish.
  • All your OST file data will move to PST except contacts.

Technique #4- Use Drag and Drop to Convert OST to PST

This method is also sometimes fruitful in converting the OST file to PST and you can check out the steps given below to use this method.

  • Launch MS Outlook and create a New PST File.
  • Then drag the mailboxes and folders to that PST file you have created.
  • Remember, this method will not drag the OST file items having contacts, Inbox, and default folders.

What if you Don’t Have an OST File?

OST Files have copies of Exchange information, that’s why it is not necessary to backup .ost files. Users can create a new copy at any time. If you don’t have an OST file and you want to extract it and then convert it to PST then you can follow the steps given below for OST File extraction.

  1. Make a Right-Click on the Email Address whose OST you want to extract.
  2. Click on the Open File Location Option.
  3. Now make right-click on the OST file you want to extract and click on Copy.
  4. Close the MS Outlook Application first and then Paste the OST file wherever you want to Paste it.

After having an OST file you can import it to any Outlook Account once you convert it to PST. If you have an OST file of one Outlook Account and you want to import it to another Outlook Account then the conversion of OST to PST is Mandatory. Once you have a PST file, you can import it to any Outlook Account.

How to Create an OST File?

You must see some simple steps that tell about the creation of an OST file. After that, we will move to the freeways that can help you to change OST to PST in Outlook.

  • Close the Outlook Application and then go to the Control Panel on your system.
  • Type Mail in the search box of your Control Panel.
  • Then click on the Mail that should be your Microsoft Outlook Profile.
  • Then a pop-up opens where you will have to click on the Show Profile option.
  • Now you can select the existing profile or even a new profile.
  • Click on Properties after selecting the profile and then in the pop-up, click on E-mail Accounts.
  • Again a pop-up menu appears where you will have to click on Settings.
  • Then in the next Windows, go to the Advance option and click on the Use Cached Exchange Mode option.

Now whenever you will work offline on Outlook, the cached data will be stored in an OST file. Enabling the Use Cached Exchange Mode setting will create the OST files.

Import the PST file after Converting from OST

  1. Open MS Outlook App to which you want to import the PST File.
  2. Click on the File tab and then click on the Open & Export Option.
  3. Then click on the Open Outlook Data File option.
  4. Finally, choose the PST file in which you have recently imported OST data and click on the OK button.

Now, you can view all the emails and mailbox items of the PST file in your Outlook Account. The above method will help you to convert OST to PST in Outlook 2019, 2016, and 2013 by implementing a program. It can work for all Outlook Versions. But there are certain drawbacks of the above method and the major drawback is you can’t convert an OST file to PST if it is saved separately on your local machine. You will need Professional Software to perform the conversion.

But let’s explore certain drawbacks of the manual conversion first and then find out how OST to PST Converter can be a good option for OST to PST Conversion.

Drawbacks of the Manual Method

  • You will need MS Outlook to be there on your System.
  • You will also have to connect your system to the MS Exchange Server.
  • This is a lengthy and time taking process.
  • A novice user might miss some important steps and also lose his crucial data.
  • You will also need a lot of technical expertise to implement the manual steps.


Well, for OST to PST conversion in Outlook 2019, 2016, and 2013 you can follow the manual methods as well but they are not easy to follow for a novice user. Moreover, it is totally up to you which conversion method you follow and saves the OST offline mailbox to PST. If you are using the SysInfoTools OST to PST Converter software, you must forget the risk of data loss because this software never fails to convert OST to PST. Experts suggest this software for conversion because manual conversion might not be easy to apply for novice users.

Frequently Asked Questions

Q. How can I Move OST File Emails to PST without Outlook?

Ans – If you want to move OST file emails into PST without installing Outlook, then use the Automated OST to PST Converter tool mentioned in the article.

Q. How can I import OST to PST using MS Outlook?

Ans – You can follow the steps given below to import OST to PST through MS Outlook:-

1. Start by opening the MS Outlook application.
2. Then select Import and Export from the File menu after opening it.
3. Click Export to a file and Next in the following window.
4. Select the Outlook data file (.PST) and press Next.
5. Choose the mailbox folder to export an OST file to a PST file.
6. Then Click Finish after browsing and selecting the folder where you wish to keep the PST file.

Q. Why are OST Files Created?

Ans – In offline mode, the OST file represents the local cache of your Exchange account. The OST files develop when users are offline or do not have an Internet connection.

Q. Can I Open an OST File in Outlook?

Ans – Yes, you can open an OST file in Outlook with the help of this write-up.

Q. What is an OST File?

Ans – An offline folder file in Microsoft Outlook is an OST file (.ost). Users can work offline and synchronize changes with the Exchange server when they next connect, thanks to offline folders. Working offline is advantageous in settings with poor or unstable connectivity.

Q. Can I Change the OST File Format to PST?

Ans – Yes, you can easily change the OST file into PST format. You can either follow the manual method or use the best OST to PST Converter Tool for the conversion.

Q. Will the above methods also convert OST to PST in Outlook 2013 and Outlook 2016?

Ans – Yes, with the help of the methods mentioned above, you can easily convert OST to PST in outlook 2013 and also in Outlook 2016

Q. How Can I Convert OST File to PST Online?

Ans – Follow these methods to convert the OST file to PST:-
1. Download OST to PST Converter Software.
2. Then Add the OST File and Choose the Emails which you want to convert in PST.
3. Choose the Saving format as PST and click on Convert.
4. Your OST file will convert to PST.

Q. Why should I use OST to PST Converter for converting OST Files to PST?

Ans – The manual methods have certain limitations and that’s why experts have recommended using the OST to PST Converter. It is an exclusive solution to convert multiple OST files into PST format. Moreover, the tool offers multiple advanced features while performing the conversion process.

Q. What would be the conversion accuracy in OST to PST Conversion?

Ans – If you want 100% accuracy in OST to PST Conversion process then the OST to PST Converter is the perfect solution for you.

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