Oversized PST files are one of the main reasons Outlook becomes slow, freezes, or starts showing corruption errors. When your PST file grows beyond safe limits, it puts your mailbox at risk. The best solution is to split large PST files into smaller, manageable parts—and the good news is you can do this safely without losing a single email.
In this guide, you’ll learn:
Why Outlook PST files become too large
Risks of oversized PST files
Different ways to split PST files
A step-by-step method to split PST files without data loss
The safest automated solution (recommended)
Let’s begin.
Why Do PST Files Become Too Large?
A PST file stores your emails, attachments, contacts, notes, and calendar items. Over time, as you receive more messages—especially those with heavy attachments—the file grows rapidly.
Common reasons include:
• Years of emails stored in one file
• Large attachments and media-heavy messages
• Outlook backups that keep increasing
• Multiple email accounts added to one profile
Problems Caused by Oversized PST Files
A large PST file may lead to:
• Slow Outlook performance
• Freezing and not responding
• Errors like “PST file cannot be opened”
• Frequent corruption
• Inaccessible emails
• Failed mailbox migrations
Splitting the PST file prevents all these issues and keeps your mailbox safe.
How to Split PST Files in Outlook Without Data Loss
Outlook does not offer a direct “Split PST” button, but you can use indirect methods or trusted tools. Below are the safest ways.
Method 1: Use Archive Feature in Outlook (Manual Method)
Outlook allows you to create smaller archive PST files based on date.
Steps:
Open Outlook.
Go to File → Info → Tools → Clean Up Old Items.
Select Archive this folder and all subfolders.
Choose the date range to move older emails.
Pick a location to save the new PST file.
Click OK.
Limitations:
• Slow process
• No option to split by size or year
• Requires careful multiple attempts
• Not useful for corrupt or inaccessible PST files
Method 2: Move Items to a New PST File Manually
This method requires you to create a new PST file and manually move items into it.
Steps:
Open Outlook.
Go to File → Account Settings → Data Files → Add.
Create a new PST file.
Drag and drop emails/folders into it.
Limitations:
• Time-consuming
• High manual effort
• Risk of missing important data
• No automation
Method 3: Split PST Files Automatically (Recommended Method)
The safest way to split a PST file without losing data is by using a dedicated PST splitting tool. Tools like Advik PST Splitter Tool provide multiple split options and ensure 100% data safety.
Split PST File Without Data Loss Using Advik PST Splitter Tool
If you want a fast, clean, and error-free process, this tool is the best choice.
Why use Advik PST Splitter?
• Split PST files by size, year, date, or folder
• Works without Outlook
• Keeps folder structure and metadata intact
• Supports password-protected, ANSI, and Unicode PST files
• Handles corrupt PST files
• Split multiple PST files in bulk mode
• Simple interface for all users
How to Split PST Files Using Advik (Step-by-Step)
Download and install Advik PST Splitter Tool.
Launch the tool and click Add PST File.
Select your desired split option:
• Split by Size
• Split by Year
• Split by Date
• Split by FolderChoose the output location.
Click Split Now.
Within minutes, your large PST file will be divided into smaller, clean, error-free PST files.
Which Method Should You Choose?
Method | Safe | Fast | Best For |
|---|---|---|---|
Manual Archive | ✅ | ❌ | Basic users with small PST files |
Manual Move | ✅ | ❌ | Folder-based cleanup |
Advik PST Splitter | ✅✅ | ✅✅ | Large, corrupt, or complex PST files |
If you want full safety and accuracy, the automated method is the best choice.
Final Thoughts
Managing an oversized PST file doesn’t have to be stressful. Whether Outlook is slowing down or your PST file is becoming unmanageable, splitting it into smaller files is the safest solution. While Outlook’s manual options exist, they take time and offer limited flexibility.
If you want a reliable, accurate, and quick process, Advik PST Splitter Tool makes the job effortless and ensures your data stays completely safe.
