How to Compress PST Files in MS Outlook 2019/2016/2013/2010/2007

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  • Published on
    July 1st, 2010
  • Updated on
    August 5, 2022
  • Read Time
    5 minutes
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Summary:-An Outlook Data File (.pst) stores all your email messages and other mailbox items and is saved on your computer. But if an Outlook data file (PST) of any format, i.e., ANSI or Unicode, reaches its maximum size or exceeds the size limit, chances are fair for corruption. In such a situation, you need to compress PST file by reducing its file size, or you can use the SysInfo PST Compress Tool, which will help you reduce PST file size efficiently.

There are two types of PST files created by Outlook. If a PST file is saved in ANSI format, it can store up to 2 GB of mailbox data. In addition, if in Unicode format, a PST file can store up to 20 GB of mailbox data (up to 50 GB in 2013, 2016, and 2019). Before going to the solution of reducing the Outlook PST file size, let’s learn the need to compress PST File size.

Why Need to Compress Outlook PST File Size?

There are many reasons why users need to reduce or compress the Outlook PST file. Some of the common causes are described below:

  • Users want to compress the PST file size because a big file leads to the possibility of corruption or damage.
  • If you have a large Outlook data file, you won’t be able to transfer or move it quickly.
  • Suppose you have a large PST file that consumes unnecessary space in your system.
  • An oversized PST file can cause serious performance issues in the Outlook client.

Methods to Compress PST File in MS Outlook

MS Outlook data files can be reduced via various methods, and here we will discuss the most accessible and secure methods to compress PST files in Outlook 2019/2016/2013/2010 and all other versions. Let’s go through the manual methods first:

Method 1: Compress MS Outlook PST Files Using the “Compact Now” Option

  1. Launch the MS Outlook application.
  2. Navigate to the File Tab.
  3. Choose Info >> Account Settings >>again Account Settings
  4. Select “Data Files”>>choose “Settings.”
  5. Click the “Compact Now” option on a popup window
  6. Finally, click OK & close the software.

Method 2: Compress PST Files Using the Mailbox Cleanup Tool

  1. Open Outlook and go to the File tab.
  2. Choose Tools >> Mailbox Cleanup.
  3. The following options will show View Mailbox Size, Find items older than, Find items more significant than, View Deleted Items Size, Empty Deleted Items, View Conflicts Size, and Empty Conflict. Select any of these accordingly.

Methods 3: Archive Outlook Old Emails to Compact PST Files

  1. Go to File >> Info.
  2. Choose Tools >> Clean Up Old Items
  3. Select the Archive this folder and all subfolders option, & then choose the folder you wish to archive.

Note: If you want to archive some specific folders, you can use different settings to create multiple Outlook data files (.pst).

  1. Include items with the “Do not Auto Archive” checkbox to archive items not present in automatic archiving.
  2. Finally, click OK to compact PST files by archiving them.

How to Compact PST File in Outlook 2010?

  1. Open the MS Outlook program on your system.
  2. Click on File tab > Info > Account Settings > again Account Settings.
  3. The Account Settings window will open. Click on the “Data Files” tab.
  4. Select the .pst file you want to compact and click on the “Settings” button.
  5. Now click on the “Compact Now” button.
  6. Outlook starts compacting your .pst file.
  7. Click on “OK” and then Close.

How to Compress Outlook PST file Size in MS Outlook 2007?

  1. Open the MS Outlook program on your system.
  2. Click on the “File” tab and select “Data File Management.”
  3. The Account Settings window will open. In the “Data Files” tab, select the .pst file you want to compact and click on “Settings.”
  4. Now click on the “Compact Now” button.
  5. Outlook starts compacting your .pst file.
  6. Once the file is compact, click “OK” and then Close.

Also Read: How to Repair Oversized Outlook PST File?

Professional Method to Compress and Reduce PST File Size in MS Outlook

Sysinfo PST Compress and Compact Tool, an exclusive tool provided by SysInfo, is a secured tool to compress and compact PST files in MS Outlook 2019/2016/2013/2010 and all other versions. It compresses large PST files in the least amount of time by removing big attachments and storing the compressed PST files in a separate folder or in the same PST itself. Furthermore, this tool works flawlessly and at ultrafast speed to reduce PST file size by removing irrelevant items.

Simple Steps to Compress PST File Size in MS Outlook

  1. Install & run the SysInfo PST Compress and Compact tool.
  2. Once you add the files, ensure PST files are not corrupted. Then click on OK.
  3. Choose the Compress option and set the location to save the resultant file.
  4. You can also add the PST file directly into Outlook.
  5. Click on the Next button to start the compressing process.
  6. Finally, click on the Close button to finish the work.

Why Choose this Software?

  • Allow Batch Compression, i.e., you can compress multiple PST files at once.
  • Reduce PST file size by removing or extracting attachment files.
  • This tool compresses PST files, including attachments.
  • PST Compress Tool allows users to attach new PST files to the outlook profile.
  • Supports PST compression of both ANSI & UNICODE PST file types.
  • PST Compact tool provides an option to apply a password to new PST files.
  • PST Compact tool saves the first 5 emails of every file after compression.


Try given manual methods in the above sections to compress PST files in MS Outlook 2019/2016/2013/2010 and other older versions. If you still having problems with those manual methods and cannot Compact PST in MS Outlook, then you can install our PST Compress and Compact tool to compress, compact & manage the PST with its wide range of functionality.

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