How to Convert ANSI PST to Unicode PST Files?

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  • Published on
    January 31st, 2017
  • Updated on
    May 8, 2023
  • Read Time
    6 minutes
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Summary:- Outlook Express is used to create an ANSI PST file whereas MS Outlook creates Unicode PST files. So, many people face difficulty when they want to access ANSI PST on MS Outlook’s latest version. So, are you the one who is searching for an easy way to convert ANSI PST to Unicode Format? If yes, then you are at the right place. In this blog, we have not only covered the direct technique to Upgrade Outlook PST but also explained the reasons and advantages of upgrading PST to Unicode PST files. Converting any PST file from ANSI to Unicode PST is a simple and straightforward process that can be done in two ways.  Either you can do the conversion manually or through SysInfo PST Upgrade and Downgrade Tool

Need for Converting ANSI PST to Unicode PST Format

  1. Unicode PST file is a better option for Outlook users as it provides enough storage space for storing mailbox data whereas ANSI is limited to 2 GB Only.
  2. There are more chances of Corruption in the ANSI PST file as it has a maximum size limit of 2 GB which is really very less.
  3. With Oversized ANSI PST, there is deterioration in Outlook performance. To overcome all these limitations and issues, you can upgrade Outlook by converting ANSI to Unicode format.

How to Convert Outlook Express ANSI PST To Unicode PST Format

There are two ways to upgrade the ANSI PST file to a Unicode PST file. Either you can try the manual method to upgrade ANSI PST or you can straightaway use the professional tool to do the same.

Manual Steps to Upgrade ANSI PST

  • Open Outlook client on your system and then you need to create a new PST file.
  • Once your PST file is created, switch to Folder List in the Navigation pane or just press Ctrl+6. This will make the copying task of Calendar, Contacts, Journal, Tasks, and Notes folders easier way.
  • Now you can move all the mailbox files from the ANSI PST file to the newly created Unicode PST file. You can even use Drag & Drop feature for this, in which you can either copy them or move the folders to the newly created Unicode PST file.
  • Once the process is completed, the ANSI PST mailbox content will be saved in the new Unicode PST file format.

With this process, your can store up to 20 to 50 GB of mailbox data.

Professional Solution: SysInfo PST Upgrade and Downgrade Tool

You can try a professional tool to upgrade Outlook PST from ANSI to Unicode format. Download free SysInfo PST Upgrade and Downgrade Software to export ANSI PST to Unicode format. This tool also contains a downgrade feature as well. With this feature, you can also downgrade Outlook by converting Unicode PST files into ANSI File format. It’s a swift and safe solution to perform PST conversion without causing any damage to original files.

Microsoft Outlook, a part of the MS Office suite, is not just an email client application. It’s also a personal information manager that provides an easy and high-end mailing environment so that users can send and receive email messages as well as organize them at great ease. Other features provided by Microsoft Outlook include a calendar, contact manager, note-taking, task manager, journal, and web browsing.

MS Outlook creates an Outlook data file on your local system to store all your mailbox stuff and data which include email messages and other stuff like a calendar. tasks etc. That Outlook data file is PST personal storage table).

Types of Outlook PST Files (ANSI PST & Unicode PST)

There are basically two types of Outlook files; ANSI and Unicode are two different formats used to save PST files as per their Outlook version. In Outlook 2002 and the older versions, the PST file is saved in ANSI format. In Outlook 2003 and the latest versions, the PST file is saved in Unicode format. ANSI is an old format and can store only up to 2 GB of mailbox data.

On the other hand, Unicode is a new format that provides a maximum size of 20 GB to 50 GB. and unfortunately, You can’t open your ANSI PST file in Outlook 2003 or above versions. Similarly, a Unicode PST file can’t be open in MS Outlook 2002 or earlier versions. Hence if the user wants to convert ANSI PST to Unicode PST file type then follow the mentioned below method or can go for some cost-effective ANSI to Unicode Converter.

Difference Between ANSI PST and Unicode PST

ANSI is a very old character encoding Unicode is the current standard in use today
ANSI programs are slower Unicode programs are faster
ANSI uses fixed-width encoding Unicode uses both fixed and variable width
ANSI Code doesn’t work on the latest systems of Outlook Unicode PST works on the latest systems of Outlook

What are the Limitations of PST Files?

Not only do ANSI PST files cross their maximum size limit but Unicode PST Files also cross the limit. Nowadays users are solely dependent on email clients, hence all the space gets overloaded with loads of PST files So both ANSI and UNICODE PST is prone to corruption. Even if a PST file does not cross maximum size but is on the verge of reaching its maximum size, causes serious problems to Outlook users which mainly include sluggish Outlook performance. If you’re using Outlook regularly in your day-to-day life, 2 GB is also damn less and is surely not enough for you. so switching from ANSI to Unicode becomes a vital step.


There are two approaches to Convert ANSI PST to Unicode PST. First is a manual trick that requires no bucks, but needs Outlook knowledge. If the person is not well versed with Outlook then there may be chances of corruption of PST files. And the other method is cost-effective and smart PST Upgrade software that converts ANSI PST to Unicode without taking much time of the user’s time the third-party software is not only very effective but also provides other features which make the conversion damn fast.

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