How to Convert OST to PST the Easy Way in 2020

By Joseph Gildred
— Last Updated:

Working with .ost files can be a notoriously futile effort if going it alone. Thankfully, there are many capable tools for scanning and converting .ost files to more workable formats, like .pst files. In fact, it’s fair to say that a good .ost to .pst converter is an essential tool in any self-respecting IT guy’s digital toolbox. In this article, we’ll be taking a look at one such tool: Stellar OST to PST Converter.

Stellar is a name that earned our esteem in early 2017, we decided to start putting together research on the best data recovery software. That weeks-long endeavor resulted in this writer’s current state of alcoholism, as well the anointing of Stellar Data Recovery best in show. It also prompted us to start looking at what other useful tools the company has to offer for the IT office.

Coming up, we’ll give you a peek at Stellar OST to PST Converter, walking you through how to use it to recover emails, calendar items and contacts from Outlook .ost files. Don’t forget to also check out our full Stellar Data Recovery review.  

Who is Stellar OST to PST Converter Converter For?

We’re guessing that if you’re reading this article, you probably already have a pretty good idea what .ost and .pst files are, so we’ll make this next part brief. 

Both are data files used by Microsoft Outlook. The information stored in these files includes all of your email messages and calendar events, so they’re pretty important. Both are also stored on your computer hard drive, copying data from a mail server and letting you access previously synced objects without having to be online.

Of the two, personal storage table (.pst)  files are more commonly used, being used for POP3 and IMAP, both protocols for web-based email accounts. An offline storage table (.ost) file, on the other hand, is used to store Outlook data when using Outlook 365, Microsoft Exchange and

A .pst file has quite a bit more flexibility than a .ost file, as it never gets deleted by Outlook and can be copied to new Outlook installations or even moved to new machines. A .ost file doesn’t provide the same luxury: it can only be opened by the Outlook profile that originally created it, meaning you can’t reuse the file.

With Stellar OST to PST Converter, you can overcome those limitations, in addition to migrating your entire email account from Exchange or Outlook 365 to a different email service. The converter is also useful for navigating the difficulties caused by Exchange server crashes or synchronization errors, or even corruptions to an .ost file caused by malware.  

Stellar OST to PST Converter has several advantages on top of that. Most notably, it can be used to search for and save individual emails within your .ost file, rather than migrating the entire thing. It can convert contacts, calendars, task, notes and journals as well.

A few other key features that we like include:

  • Preview of recovered items before recovery
  • Conversion of encrypted .ost files
  • Save converted files as .msg, .eml, .rtf, .html and .pdf

We’ll take a look at some other, license-specific features in the next section.

Stellar OST to PST License Options

Stellar’s conversion software will let you preview emails and calendars prior to conversion. While there’s a free version of the tool, though, it limits you to 20 conversions before you have to subscribe.

For businesses and IT professionals that need more mileage out of the tool, you can purchase a perpetual (lifetime) license for either a single or multiple machines. The tools have no file size limitations and come with free technical support.

 CorporateTechnicianOutlook Toolkit
InstallationSingle systemMultiple systemsMultiple systems

The multi-machine Technician license has a few other perks over the single-machine Corporate license that will appeal to IT types, including:

  • Batch conversion: convert multiple .ost files
  • Compact and split .pst files
  • Save Outlooks contacts to .csv format

The Outlook Toolkit, meanwhile, is the best of the three, thanks to handy tools for IT professionals to manage a range of mail problems like repairing corrupt .pst files and recovering attachments and .pst passwords.

How to Convert OST Files with Stellar

One of the reasons we became fans of Stellar at is that the user experience for most of the company’s products is blissfully straightforward without skimping on features, which frankly you don’t get with many other IT products.

However, you might need some help getting started, or perhaps just want to get a basic idea of the process before adding Stellar OST to PST Converter to your IT toolbox. In light of that, up next we’ll take a look at the basic conversion process.

Step One: Install the Program and Run Scan

The first thing you need to do, of course, is to install the software. That’ll just take a minute or two, even if you’re signing up for service. Stellar will send you the product download link and an activation key as soon as your payment gets processed.

Once installed, start the client. A small window on top of the main client will let you select the .ost file you want to convert.

You can either browse your file system for it, or let the converter scan your drive for .ost files. A scan takes under ten seconds based on our testing, so unless you know exactly where to look, that’s probably the faster approach.  

Once you’ve got your file, highlight it and click the “convert” button. The client will begin the conversion process, which does not keep you waiting.

In our case, it took about a second, though admittedly our .ost file was pretty small at around 16MB (.ost files in Outlook 2016 can grow to 50GB by default, although you can increase that limit if you want).   

Step Two: Working With Your Scanned OST File

Once your .ost file has been scanned, you can browse its contents right from within the Stellar converter desktop client.

The left-most column of the client includes a tree menu where you’ll find subsections for your calendars, contacts, inbox, junk mail, journal, deleted items and other Outlook folders.

The next column contains objects stored in the folder you pick. For example, if you choose “inbox,” the column will display a list of emails in your inbox. The third column provides a preview of the object itself, for example, an email.

You can save either the converted file or the scan itself, which is a .dat file. When saving the entire file, you’ll have the option of choosing whether you want to save it as a .pst, .msg, .eml, .rtf, .html or .pdf file type.

If you don’t need the entire file and just want to save, say, a single email, you can do that, too. Right-click on the mail and choose the file format you want to save it in.

And that is all there is to it.

Final Thoughts

Working with .ost files is normally an impossible task, but Stellar OST to PST Converter fixes all that. It fast, simple and as powerful as it needs to be. Basically, it’s the perfect tool for IT guys looking to impress the rest of the office without actually having to do much of anything other than clicking a few buttons. And we’re all on board with that.

If you’re looking for a complete tool, we’d suggest splurging on the full Outlook Toolkit, since it can also repair corrupt .pst files.  Let us know your thoughts in the comments below and thanks for reading.