How to Convert from OST to PST

The Outlook PST files are a great way to import and export mail and are often used for making backups of your mail. OST files, on the other hand, can’t be imported, but they do contain all your mail items. So how can we convert OST to PST, and preferably for free of course?

To recover your email items from the OST file, we will need to convert the OST file to PST. We can do this for free with Outlook or by using one of the converter tools that are available on market, like Stellar Converter or SysTools.

In this article, I will explain how you can convert your OST file to PST for free using Outlook and we will take a look at two of the converter tools.

Converting OST to PST for Free

There are multiple ways to convert from OST to PST manually (for free), but all solutions require that you have access to the Outlook profile. The reason for this is that the OST file can only be opened with the same profile.

You don’t need to have internet access when you want to export your mailbox to a PST file. Having access to the Outlook profile is enough to export the OST file to PST.

Convert OST to PST

Time needed: 5 minutes

To manually convert an OST file to PST we will need to use Outlook. Make sure you have access to the original Outlook profile.

  1. Open Outlook and click on File

  2. Select Open & Export and choose Import/Export

    Convert OST to PST

  3. Select Export to a file

    Export to PST

  4. Select Outlook Data File (.pst)

    OST to PST Converter

  5. Select the folder you want to export or select the whole account.

    Make sure Include subfolders is selected

    Convert from OST to PST for free

  6. Click Next and choose a location for the export and click finish

    When the export is finished you will have a PST file that you can use to import the mail into another account.

Best OST to PST Converter

If you don’t have access to the Outlook profile then your only option is to use an OST to PST converter, a paid third-party solution. I understand that you are looking for a method to convert OST files for free, but there are no free tools that can do this.

And yes, there are a lot of tools that claim to be free, but they all come with some sort of limitation. They only export a limited amount of items or are unable to open the OST file without the Outlook profile (and if you have access to the Outlook profile, you can use the manual method described earlier)

There are two tools on the market that are well-known and I highly recommend. Both do a great job when it comes to convert OST files to PST and they are able to recover every bit of data out of your OST files.

Stellar Converter for OST

Stellar Converter for OST is really a powerful tool that can convert any OST file (encrypted or IMAP OST files) to PST while keeping the structure of your inbox intact. The tool can be used with OST files from any Outlook version, it will simply extract all emails, calendars, contacts, and attachments from it.


The price for Stellar Converter for OST starts at $79. You can get a 10% discount with the code EMAILOFF10.

To tool is easy to use and doesn’t require any technical knowledge. When you open Stellar Converter for OST it will automatically find all OST files on your computer. To get started, select the OST file that you want to convert

stellar converter for ost
Depending on the OST file size it can take a few seconds up to a minute to convert your OST file.

Stellar has a look and feel that comes close to Outlook, and allows you to browse and preview your mail items before you start the export.

best ost to pst converter

Stellar Converter for OST allows you to select the items that you want to export. This way you can only export the items that you really need. After you have selected the items, click Save Converted File. You can now save the result to the following file formats:

  • PST
  • MSG
  • EML
  • RTF
  • HTML
  • PDF
convert ost to pst

You can also use Stellar to find one or more emails from a recipient or between dates and export only the results.

Stellar offers a free version of their OST to PST Converter, which is limited to recovering 20 items per folder. Even though they offer a 30 money-back guarantee, it’s still a good idea to test the free version first with the OST file that you want to recover.

The software supports all Outlook versions. The price for Stellar Converter for OST starts at $79. You can get a 10% discount with the code EMAILOFF10.

SysTools OST Converter

SysTools OST Converter is a really powerful converter that can export corrupted, damaged, encrypted, and even Password protected OST files. The look and feel of the tool are based on Outlook 2007 / 2010, making it really easy to navigate and search through the OST file.

SysTools Convert OST to PST

When you open SysTools OST Converter you will first need to select your OST file. You can find the OST file in the Local AppData folder of the user:


Depending on the size of the OST file, it takes a couple of minutes to open the file. You will find the inbox of the user in the folder tree under Root – Mailbox > IPM_SUBTREE > Inbox.

When you click through the folder tree on the left side you will notice that all the data is recoverable, including contacts, calendar items, content from shared mailboxes, etc.

Exporting OST File to PST

When you have found the data that you need, you probably want to export it. SysTools supports different export file types, including:

  • PST
  • PDF
  • MBOX
  • MSG
  • EML
  • HTML
ost to pst Converter

You can select the folder that you need, choose the destination and simply click on export. What great is about SysTools is that you can first test the tool with your OST file without buying anything.

You can simply download the SysTools OST Converter and run in demo mode to first test it. And with a price of $49 is it really affordable as well.

With the code LAZYAD25OFF you can get a 25% discount on your purchase!

OST to PST Converter Online

There are a couple of online OST to PST converter services on the internet. They may appear to be a free service, but they are definitely not free. You will have to pay around $10 per GB for the conversion.

Also keep in mind that you are uploading a complete mailbox, with all the personal and maybe sensitive data, to a company that you don’t know.


You can convert an OST file to PST for free, but only when you have access to the Outlook profile. When you only have the OST file, then your only option is to use one of the recovery tools.

The free tools that you will find on the internet are all limited. They may show you the content of the OST file, but you can only export a limited amount of items.

A great tool, like SysTools or Stellar, will save you a lot of time when it comes to converting your OST file.

5 thoughts on “How to Convert from OST to PST”

  1. Congratulations Ruud!

    Great article on a topic that is often taken for granted, yet complex and sensitive. Users want to preserve their emails, contacts and all the stuff!!

    I have just been working with a client switching from his old IMAP provider to Google. Using Outlook as a mail client.

    I have used the Google Workspace Sync for Microsoft Outlook (GWSMO) tool. And it has apparently done good with the emails. But I don’t see the contacts!!

    This tool generates a new profile in Outlook and creates its own account, already synchronized with Google’s. Which, by the way, is based on .PST and not .OST.

    The question now is that I need to recover the pre-existing contacts in Outlook. And for this I only have the old source .OST, though I can no longer create a profile using the same email account.

    So I am in the position to directly convert the .OST to .PST.

    And your article has helped me a lot. Corroborating what I have already found: the payment tools.

    KnowltBetter’s note seems very interesting to me. But I don’t know how to do point 3: create a dummy account.

  2. If you have orphaned OST Files and not bound to Outlook anymore, no big deal – you still can recover and convert them to PST and the best FOR FREE:
    No need for such expensive Tools as StellarInfo or CoolUtils whatever if you just want your messsages recovered.


    1. Open Outlook

    2. MOSTLY IMPORTANT disable automatic Send/Receive (Outlook may not sync automatically)

    3. Create a new dummy-mailbox in outlook that works as a container. We need the container-.OST in a minute as sort of a jar.

    4. Open the local folder where this .OST ist stored

    5. Close Outlook

    6. Now, take your actual .OST File that you need to convert (and which is not in Outlook anymore – if it were you wouldn’t have to do that)

    7. Rename your .OST to the container-.OST filename, copy and overwrite the container-OST with yours.

    8. Open Outlook

    9. Use Import/Export Function and follow the steps to export your dummy-mailbox as PST.

    10. Repeat that for all your orphaned OSTs

    You even can move those messages to another existing mailbox.

    Mailbox settings doesn’t matter… it just works.

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