Reduce Size of OLM File in Windows- Import OLM to PST Files

Reduce Size of OLM File in Windows- Import OLM to PST Files
5 min read

A single OLM file can save multiple folders. As a result, it increases the size of the file. If an OLM file exceeds the size limit, then the chances of data being corrupted. Hence, we are here to provide you with a method that can reduce size of OLM file in Windows.

Whenever users need to export or archive the data from Mac Outlook, It uses an OLM file. OLM file is a database file that stores all mailbox items like emails, contacts, calendars, etc. Then, an OLM file is stored on the hard drive. Officially, there is no size limit for OLM file. But if the file exceeds 2 GB, then there will be a high chance of corruption. Therefore, users should reduce OLM file into multiple files.

Reasons to Reduce Size of OLM File in Windows

With the large OLM file, it affects data and the working of the file. In that case, we split the large OLM file into several files. There are also other reasons why we should split the file.

  • Large oversized OLM files hamper the performance of Mac Outlook.
  • You can resolve the problem of corruption in a large OLM file.
  • The large size of OLM files leads to loss of data and data inconsistency.

Method to Reduce Size of OLM File in Windows

OLM file is only used in Outlook for mac, not Windows Outlook. Also, there are no features in Mac Outlook that you can split the file into multiple files. You can only export large OLM files and divide the data into contacts, calendars, etc. For this reason, there is no manual method available. But there is a method, which is free to use and can easily reduce OLM files in Windows. That is to use a professional method.

Professional Method to Reduce Size of OLM File in Windows

To split a large OLM file into several files. We need to first convert the OLM file into a PST file. A PST file is a Personal Storage Table, that is used to save emails, events, calendars, etc. It is used in Windows Outlook. Both files are used in different Operating systems. And there is no direct way to convert the files. Therefore, we use a professional tool. SysTools OLM to PST converter is a software that converts OLM into PST file. It also offers various features like.

Features of Software

  • Before exporting the files, you can preview your selected OLM files.
  • It provides the option to split large OLM files into several PST files.
  • During the conversion, it maintains folder hierarchy and data integrity.
  • You can also name your resulting converted file. 
  • This tool allows you to save a copy of a scanned OLM file.

Steps to Convert OLM File into PST 

  • Download and open the software. Click on the Add File option at the top of the screen.
  • Browse your OLM file by clicking the Browse button “…”
  • Browse specific OLM source locations and click on the Open button.
  • Click on Add file option to start the scanning process.
  • After completing the scan, press Yes to save the scanned copy. 
  • Now, you can preview your files in different modes, such as Hex, MIME, HTML, etc.
  • Click on the Export option to convert OLM file to PST file. Or click on selected export to import selected OLM files.
  • Now, click on PST as select export type. Select the Advance setting option.
  • Here, you see three features: split PST file, date filter option, and categories. Select the split PST file option and enter the value.
  • Once you are ready to export, click on the save option. Press OK.
  •  Select the location of your converted files by clicking the Browse option.
  • Click on the maintain folder hierarchy checkbox. At last, select the export option.


In this article, we learn that large OLM file can cause various problems. So, to solve these problems, we should reduce size of OLM file in Windows. There is no manual method as OLM file does not support Windows OS. Therefore, we use a third-party tool to reduce the size of OLM file. This expert-recommended tool has an option to split PST files, that splits your large OLM file into prescribed sizes. This tool is free to use and can be downloaded in any Windows version.

Frequently Asked Questions

Q1. How do I open an OLM file on Windows?

Ans. You can easily open your OLM file in Windows by downloading the software mentioned above.

Q2. How to reduce the size of an OLM file?

Ans. Reduce the size of a large OLM file using the OLM to PST converter mentioned in this article.

Q3. What is the size limit of an OLM file?

Ans. The size limit of an OLM file is 2 GB.

Avantika Singh 2
Joined: 8 months ago
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