OST PST Viewer for Outlook

PST Walker

Open PST and OST files in a few clicks without Microsoft Outlook. View, search, and export Calendar, Contacts, or Tasks alongside your email to PST and other file formats.

  • Recover encrypted, password protected, large-sized files, and recover even deleted items
  • Open corrupted PST and OST connected or orphaned Outlook data files
  • HEX analysis of email headers and all message properties
  • Boolean search, Outlook-style filtering, Built-in search filters
  • Reply and Forward email files using your default email client

PST Walker Portable Version (.zip) - No Installation Required

OST PST Viewer for Outlook

When to use PST File Viewer

Email Preview

Portable viewer for .pst and .ost files

PST Walker is more than just a PST Viewer. You can also extract emails and attachments in bulk and convert your email, calendar, contacts, and tasks to .pst, .mbox (Thunderbird), .msg, and .eml file formats.

Search PST and OST Files

Search multiple PST and OST files

PST Walker’s search box is a powerful tool to help you search content and attachments of Outlook data files. In addition to searching for different words and phrases, you can use various boolean operators and keywords to narrow your search results.

  • Search in subject, body, attachments, sender name, recipients, size and etc.
  • Scans both email messages and attached emails
  • Supports Active Directory/Exchange x.500 email addresses
  • Highly efficient search algorithms, you spend less time waiting for results
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Filtering PST Files

Built-in search filters

PST Walker provides you with a number of built-in search filters. To use the built-in filters, right click on the column header and select Filtering. Based on your preference, you can use Advanced Search and built-in search filters at the same time.

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HEX Analysis of MSG File

HEX Analysis of PST Files

Outlook data files (.pst and .ost) contain numerous metadata fields (MAPI properties) that can be useful for digital forensic analysis of emails.

PST file specifies five storage elements, each representing one major component of the Message object and a number of streams are contained within those storages, each stream representing a property (or a set of properties) of that component.

The storages are: Recipient object storage, Attachment object storage, Embedded Message object storage, Custom attachment storage, Named property mapping storage.

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How it works?

Step 1: Launch PST Walker and select the folder in the All Folders pane.

OST PST Viewer for Outlook See All Screenshots


Home License

Personal Use Only


  • Open PST file without Outlook
  • Open OST file without Exchange
  • View Emails and Attachments
  • Filter and Sort Emails
  • Multiple Preview Modes
  • Support Outlook 2021, 2019, 2016, 2013, 2010, etc.
Business License

For Business Entities


  • Includes all features of Home
  • Advanced Search Options
  • Command Line Options
  • Recover permanently deleted emails
  • Convert and extract emails in bulk
  • Forensic Analysis of PST and OST files
Citrix/TS License

Concurrent Users (CCU)


  • Includes all features of Business
  • Improved scanning and saving speed
  • Concurrent-user simultaneously accessing the Software on Citrix/TS computer

Technical Specifications

Product Icon
About Product
PST Viewer
Version: 6.21
License: Named User, Single/Concurrent Use
Interface Languages: English, German, Dutch, Spanish, Portuguese (Brazil)
Release Date: October, 2022
Download: Portable and Installer versions.
System Requirements
System Requirements
Processor: Intel-compatible (x86, x64)
Memory: 1 GB minimum (4 GB recommended)
Hard Disk: 50 MB for installation files
Operating System: Microsoft® Windows 11 / 10 / 8.1 / 8 / 7
Prerequisites: Microsoft .NET Framework 4.0 or higher

Product Related Articles

How to use PST Walker

This guide explains how to open, find and extract emails from .pst files and .ost files with portable PST Viewer.

Recover Outlook Rules and Alerts

Find hidden Outlook rules and alerts using MAPI properties. Export Outlook rules and alerts to rwz files. Import rules and alerts into Outlook. Supports corrupted, orphan, protected pst and ost files.

Recover deleted folder and emails in Outlook

Accidentally and permanently deleted folder in Outlook? Recover deleted folder (and all its emails, messages, contacts) in Outlook with PST Walker recovery tool. Supports both PST file recovery and OST file recovery.

Search multiple .pst and .ost files without Outlook

Boolean search, Excel-like filtering, instant search. Supports any .pst and .ost files: corrupted, orpah, archive, password protected and encrypted files. Export search results to numerous formats.

Convert Outlook data files to Thunderbird (MBOX)

The normal Thunderbird import process requires that you have a compatible version of Outlook installed on your computer. If you do not have Outlook installed, there are alternatives as noted below.

Email Investigations and Digital Forensics

Email messages contain numerous MAPI properties that can be useful for digital forensic analysis of emails. This article explore how to gather and analyze data related to email investigation and forensic analysis.

Boolean Search Syntax

This guide explains boolean search operators, functions and wildcards (AND, OR, NOT, ALL, ATLEASTONE, NEITHER, NOTALL, ?, *)

Sort and group email files and messages

Sort, arrange and group your email files and messages in a way that's helpful to you. For example, group by the name of the sender or the recipient and sort by the date of the email message, its size, and other options.