Compress large PST File Effortlessly Using 3 Methods

We have observed that many Outlook users keep on working using Outlook to send and receive emails Tasks, Calendars, Contacts, Notes etc. As all the data is stored in a PST file. Sooner the PST files become mushroom as it gets oversized. At some point, it stops storing data by showing Oversized PST errors. At this time, it becomes difficult to store data. Moreover, the functioning of the Outlook application slows down, and the email loading time increases. After facing these issues, the user now tries to look for a solution for how to compress large PST files. So, that they can create some space to store data in the PST file.

So, with the help of this article, we will explain some methods that can be used by the users to shrink the PST file in Outlook.

What happens When User’s PST Files Gets Oversized?

Oftentimes, users start facing trouble when the PST file size reaches its maximum size limit. And it requires to reduce PST file size.

  • The functioning of MS Outlook gets slow.
  • Several files in PST get inaccessible in Outlook.
  • Outlook starts to perform inappropriately.
  • Takes more time to open or load the files in PST.
  • Sometimes while accessing a data in PST file, the application crashes suddenly.

Therefore, it becomes a responsibility to maintain the PST files and take necessary action when the PST file is about to get oversized. Here, the users can compress the files to maintain or improve the application performance. This makes it easier for the users to use Outlook to work efficiently without facing any kind of issues or interruptions.

Now, let’s see some methods that a user can use to compress large PST files using Outlook.

Methods to Reduce PST File Size in Outlook 2007, 2010, 2013, 2016 Version

In this section, we have explained the process and steps to manually compact the size of the PST file in different Outlook versions. Please look at the steps carefully and implement them.

Method 1:  Compact the OST Files Using the Outlook Application

Here users can compress both OST and PST files.

  • To compress the OST file – the Outlook account must IMAP configured in the 2016 and 2013 versions.
  • For PST- the Outlook account must be POP configured in the 2016 and 2013 versions.

For Outlook Users having 2010, 2013 and 2016 Version

  1. Open the Outlook application on the machine and then press the File tab located the in top right corner.
  2. Under the Info section, in Account Settings press the Account settings option.
  3. When the Account Settings window pops up, select the Data Files, and choose the PST file to compress.
  4. Now, press the settings tab, check the file path mentioned correctly and hit on the Compact button.

For Outlook Users Having 2007 Version

  1. Launch the Outlook application and go to the file option.
  2. There, the user will find the option “Data File Management”.
  3. After that press the “Data File” button, then choose the PST file to compress.
  4. After PST file selection is done, select the Settings tab and press the button “Compact Now” and hit Ok.

Method 2: Using the Clean-up Tool Available in Outlook to Compress Large PST Files

Another option is there by cleaning the mailbox data. To remove unwanted or duplicate data from PST files.

  1. In Outlook application>>File tab>>Tools>>Mailbox Clean up
  2. Options like View Mailbox Size, find items older than, Find items larger than, View Deleted Items Size, Empty Deleted Items, View Conflicts Size, and Empty Conflict will appear on the screen, choose any available option.

Using the Smartest Technique to Compress Large PST Files

Compressing the PST files manually can be difficult when a user is having multiple PST files. In this case, it’s better to use the Software for Compressing Outlook PST Files to reduce batch PST file size at once. This tool has various features that help to reduce PST file size.

  • It helps to shrink large/oversized PST files by Extracting, Removing, and Saving mailbox attachments.
  • Using this utility, users can compress Batch PST files.
  • Without any data loss, it compresses the PST file to its minimum size.
  • This tool is compatible with both ANSI and UNICODE PST files and also supports all versions of MS Outlook and windows.

Guided Steps to Compress Large PST Files Using the Software

  • Download and launch the software to compress Outlook PST files, and press the Add file/Folders to load the files.

compress large Outlook PST files

  • Choose the PST file that the user wants to compact.

choose the PST files

  • Now fix the path where the user wants to save the compressed PST file.

set the destination path

  • Finally, to reduce PST file size, hit on the Compress PST button to initiate the process.

press the compress button

  • Next, select from the available compression options and hit on the Compress button.

compress large Outlook PST files

Also Read: How to Migrate Earthlink Emails to Gmail


In this post, we have talked about the methods that a user can use to compress large PST files. Here, we have discussed the manual solution by explaining guided steps for Outlook versions 2007,2010,2013,2016. Moreover, we have explained the automated solution to shrink PST file size and later users can add more data to the PST file.