How to Reduce PST File Size in Outlook 2019, 2016, 2013, 2010

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In this blog, we cover one of the most common queries of Outlook users related to the Outlook data files – how to reduce PST file size in Outlook. If you are searching for the same, this article will guide you with viable techniques and the best solution i.e. DRS Split PST tool to resolve the issue by splitting the oversized PST. So, read it till the end.

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PST files are the Outlook data files that store the mailbox information into the system. These files are ideal for creating a backup of your email account data. So, you can recover your valuable mailbox data when needed. Moreover, the size of Outlook PST files increases with the growth of mailbox size.

An increase in the size of the PST file is allowable up to a threshold limit. After exceeding the limit, these files start showing error messages and become prone to corruption. An easy way to tackle this situation is to reduce PST file size.

Now, you can reduce the size of a PST file through multiple techniques. But all these methods have some pros and cons. So, you cannot shrink or compact PST file size by any random procedure. Before learning how to shrink a PST file, let us explore the need to compress PST file size.

Why Should You Reduce PST File Size?

A small-sized Outlook PST file is beneficial in every way. Similarly, a large PST is always harmful. An oversized PST file adversely impacts the system. We are discussing some of the major reasons for compressing Outlook PST files.

  • A large Outlook PST file slows down the processing of Outlook applications. It reduces the efficiency and performance of the email client.
  • It covers more space and hinders the working of other applications. The maximum storage capacity of a PST file is 50 GB in all the latest versions of MS Outlook.
  • The Outlook PST file will tend to corrupt when reaching closer to the threshold limit. The most common error is that the PST file is too large in size.

Because of all the above reasons, it becomes necessary for every user to reduce PST file size.

How to Reduce the Size of PST File in Outlook 2019, 2016, 2013, 2010

Considering the standard techniques, there are two ways to compact Outlook PST files. These procedures are free of cost and effective. You can easily perform them in all the latest versions of MS Outlook.

#1. Use the Empty the Deleted Items Folder Feature

It is the most secure and effective way for shrinking PST files. Follow the steps below to empty the deleted items folder.

  • Open the Outlook application and press the File
  • From the Info tab, click on the Tools icon and select the Mailbox Cleanup
  • It will open the Mailbox Cleanup Click on the View Deleted Items Size button.
  • Now, select the Empty button to permanently remove all the deleted items.


The above method is appropriate only when the deleted items folder has a considerable size. However, you can opt for another technique when you have nothing in the deleted items folder.

#2. Compact Now Feature of MS Outlook

MS Outlook has a built-in feature to compress PST files. It is a safe and reliable option.

  • Open MS Outlook and click on the File
  • Now, in the Info tab, click on the Account Settings
  • Choose the Account Settings option from the list.
  • After that, select the Data Files tab in the Account Settings
  • Choose a particular mailbox account and click on the Settings icon.


  • In the new wizard, hit the Compact Now button.


Both the above techniques are effective. However, in reducing PST file size, the chances of file corruption are high. Apart from that, there are other limitations of compressing the Outlook file.

Drawbacks of Shrinking PST File

  • Using the compact feature multiple times is not safe for PST files. So, it is not a permanent solution.
  • If the deleted items folder is already empty, you can reduce the PST file size by cleaning the trash folder.
  • Chances of file corruption are high when compressing the file from its original size. Sometimes, the file becomes inaccessible, and you may lose your precious data.

If you want to keep your mailbox data safe and secure, the ideal way is to split the Outlook PST files.

Reduce PST File Size using DRS PST Splitter Software

DRS PST Splitter Tool is the most recommended software to split the Outlook PST files into various smaller files. It will reduce PST file size by dividing a large-sized PST file into multiple smaller files. So, this tool allows you to compact PST files without opening Outlook. Moreover, it provides you all the advanced features that customize the process as per your requirement. It is an ideal alternative to shrinking PST files as it does not damage the file content. Let us understand the working of this unmatched utility.

  • Download the DRS PST Splitter software and run it as administrator.

launch pst splitter

  • Click on the Add File(s) button to add the PST file.

Add files

  • Select a file from the system and press the Open button.

open PST file

  • Now, click on the Next button to proceed further.


  • Select the desired mailbox folders and choose splitting criteria – split by size, date, sender, or folder, hit Next.

split pst by size

  • After selecting Split by size, opt for additional features and destination path.

pst file size

  • At last, click on the Split button to divide the large size PST file.



You can adopt multiple techniques to reduce PST file size in Outlook 2007. But it is not an effective way to maintain data integrity. Therefore, breaking the large-sized Outlook PST file is the best solution to manage your Outlook data file without losing the file content. To serve the purpose the ideal solution is the advanced DRS PST Splitter Tool.

Frequently Asked Questions

Q 1: What do I do when my PST file is too big?

Ans: A large size PST file results in different Outlook issues. So, you should reduce the size of Outlook PST files. It will free up the unavailable space and improve the speed and efficiency of Outlook.

Q 2: How do I change the size of my Outlook PST file?

Ans: MS Outlook provides various inbuilt options to reduce PST file size. The Compact feature allows you to shrink the Outlook data file. Also, you can opt to empty the deleted items folder option and permanently delete unnecessary emails from the mailbox.

Q 3: How can I reduce the size of my PST file without Outlook?

Ans: The best approach to reduce the size of a large PST file is by splitting it into smaller files. You can use the advanced PST Splitter software to easily divide the Outlook PST files.

Q 4: What is the size limit for Outlook PST file?

Ans: The current storage limit for the Outlook PST file is 50 GB. However, it is advised to keep the size of the PST file small for better functioning of Outlook.

Q 5: How do I change the PST size in Outlook 2016?

Ans: You can reduce the PST file size in Outlook 2016 and other Outlook versions by using various techniques. The inbuilt features of Outlook are effective but are not a permanent solution. Therefore, splitting the Outlook PST files is the best solution to compact PST files.

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