OST Viewer



Free OST File Viewer Tool

(Average Rating 4.8 Based on 430 Reviews)

Microsoft Outlook OST Viewer is a versatile software that allows you to examine and preview OST files in a seamless manner. With this OST viewer software, you can access/view Outlook OST file data, such as emails, contacts, and calendar with attachments. The software allows user's to easily read OST files even if they are corrupted, password protected, or encrypted. This is the best software to open OST file without Exchange Server and Outlook environment on Windows OS.

  • OST Viewer Allows to View Emails, Contacts, Calendars, Tasks, Notes, and Journals
  • Browse OST File with Email Attachments Without Outlook & Exchange Server
  • Pro Version with 8 View Modes (Hex, Mime, Header, etc.) to Analyze Emails in Depth
  • Independent and Standalone OST Viewer Software to Speed up Email Management
  • Allows Users to Read Normal, Corrupt, Password Protected, and Encrypted OST Files
  • OST File Viewer to Search Emails Within OST Files with Advanced Search Option
  • OST Explorer Allows to Read OST Files of Any Size without Any Limitation
  • Supports OST Files from Outlook 2021, 2019, 2016, 2013, 2010, and Below Versions
  • OST Reader Compatible with Windows OS 11, 10, 8 & Windows Server 2019, 2016, 2012 R2, 2008
  • Version for Have Multiple Preview Mode, Advance Search, Print Feature
  • Multiple Export Options are available in Pro Plus Version with OST Viewer Features

Comparison Betwenn OST Viewer, Pro, & Pro+ Version

OST viewer comes with different versions to provide a variety of features. Here is an detailed list of the features users can opt with every version:

Best OST Viewer

OST Viewer

When users use this OST reader on their PC, users will be get access to a lots of features

  • Read Entire OST Files
  • 8 different preview modes handy to view the information of the OST file.
  • Preview All Items: Emails, calendar, contacts, tasks, notes and journal

OST viewer Pro Version

Pro Version

When users upgrade to OST viewer pro version, then users will get few additional features:

Features of OST Viewer

  • Search for OST Files within a Particular Drive or Across All Drives.
  • Allow Multiple Files Processing at Same Time.
  • Remove SMIME / OpenPGP Encryption from OST File
  • Advanced Search Option with Multiple Conditions.
  • OST Viewer Allows to Export Complete Data into PDF.
  • OST File Reader Allows to Print OST Emails.

Steps to Use Viewer Pro

Pro Plus Version of OST Viewer

Pro Plus Version

OST Viewer Pro Plus is the most advanced edition, comes with the multiple features.

Features of Outlook OST Viewer Pro


  • Export All Data into PST Format
  • Convert Emails into MBOX format
  • Convert All Items into Individual MSG File
  • Export Only Emails in the form of EML or EMLX

Steps to Use Viewer Pro+

FreeViewer Recoginitions & Awards

Most Popular OST Reader Software for All Outlook Users

FreeViewer OST Viewer

3 Step Process to Use OST File Viewer Tool

OST File Viewer – Overview

Get a Brief Overview of Free Microsoft OST Viewer Tool

Microsoft OST Viewer Tool Characteristics

The software provides multiple tabs for easy viewing experience as well as better navigation. Each tab will help you to view emails with a different perspective.

Distinguishing Features of OST File Viewer

  • View OST File Emails, Contacts Details, Journals, Calendars, Tasks and Notes that you have saved.
  • View emails from different OST files and folders under a single navigation panel.
  • In-Depth Email analysis using 8 different tabs that are designed to serve unique tasks.
  • Free OST Reader Software can also be used for forensic analysis purpose.
  • The software is simple to use, free to download and can be run on minimum hardware resources.
  • The Free OST Reader Software comes with 32 & 64 bit OST file support.
  • View normal OST files, corrupt OST files as well as password protected OST files.
  • View Exchange OST files without any limitations.
  • Maintains data integrity of the Outlook files.

Basic Information Regarding OST Extension

When emails are configured with Microsoft Exchange Server or IMAP protocol, then all the information related to your email id gets stored in the .ost format. The OST file is an offline version of the data that exist on the server and is viewable to the user even if there is no connectivity with the Exchange Server. All the changes made by the user are synchronized automatically when the connectivity is regained.

Download Microsoft Outlook Free OST Viewer

Download OST File Viewer software free demo version to easily browse and read the content of OST files. The utility displays the data of OST files without connecting to Microsoft Server and help you view offline OST files with associated attachments. You can preview the email messages, contacts, calendar items, notes, etc. In addition to this, you can also view information such as the date of the message, who sent it and who received it. Along with normal OST files, the OST viewer also displays the contents of corrupted and password protected OST files. The OST reader freeware works great on all the versions of Windows 11 (64 bit), 10, 8, 7 (32 bit or 64 bit) and Windows Server 2019, 2016, 2012 R2, 2008.

An OST file is an offline folder in Microsoft Outlook. With the help of these offline folders, users can work offline and then synchronize the changes with the Exchange Server when Internet restored. OST explorer easily extracts the information from the above defined OST files without having Microsoft email clients installed. Using this software, you can preview all the contents available within your OST file.

A Complete OST File Analysis Tool

The Offline OST Viewer software enables users to perform extensive research and analysis on the OST data. Applying the search query parameters allows you to retrieve back only the relevant information from the data and after that the targeted email can be further analyzed using the various tabs (e.g. Hex Analysis).

OST files are just replicas of all the information that exists on the configured server. The user can make any changes in the content which then gets reflected on the server side as well.

Prominent Features of FreeViewer Outlook OST Viewer Software

Free Download Microsoft OST Viewer Software to View Outlook OST File

Standalone Application

Standalone OST Viewer Tool

OST Viewer is a standalone tool to read OST file emails and easily browse OST file attachments, contacts, calendars, tasks, notes, and journals. The OST file reader is designed to help users view normal, corrupt, password-protected, or encrypted OST files in an easy and secure way. This software does not require connectivity with Exchange Server to read OST files. You can freely download and install the application in Windows OS 11, 10, 8, 7, etc..

Browse OST File

View OST File With Attachments

The OST file (Offline Storage Table) created by Microsoft Exchange Server contains crucial information such as email details, appointment related data, task, and notes among other information. To view OST files with attachments, users need to have a supportive application such as Outlook or Exchange Server. The best OST reader tool allows users to browse and view backup OST file emails and attachments with all the important information.

OST File Forensic

Forensic Analysis of OST File

Unique and free OST reader application lets a user analyze Microsoft Outlook OST files even without having any password or username details of the mailbox. It is the perfect OST viewer tool for forensic email investigators to browse OST files with multiple view options like Normal, Properties and Attachments.

Export Offline OST

Export OST to Portable Format

The OST File Viewer Pro version allows users to easily transfer the .ost data file into portable file format for easy access and sharing purposes. Users can also perform selective email analysis and get the output in the portable format. OST Viewer Pro will enable users to perform OST to Portable Document Format conversion.

Advance OST Search

Advanced Search Option

The Microsoft OST File Reader application ha has the feature Advanced Search Option which makes it easier for users to search for a particular OST file among various files. Users can also apply filters, such as To and Bcc, for more effective search results. One can also make use of operators such as AND/OR to make the search more precise. Also, get the export option to save searched emails and their attachments into PDF format.

Update Pro Version

Upgrade to OST Viewer Pro Version

In order to take benefits of the advanced features of OST File Viewer, the user can upgrade to Microsoft OST Viewer PRO version. With this version, one can easily examine the OST file and export it to the Portable Document Format. One can easily upgrade to PRO version directly from the Software interface. Use this software to view, search, analyze or export normal, damaged or password protected OST files.

OST Viewer Software - Specifications

Free Download OST Viewer Tool to Read OST Files and Thier Attachments

Software Download

Size: 18.1 MB

Version: 5.0

Trial Limitations

The OST Viewer(Free version) Only Preview OST Files and thier Attachments, to use the Advance Search Option & Export OST Emails into PDF Format upgrade/switch to Pro version.

System Specifications

Hard Disk Space
100 MB of free hard disk space required

4 GB of RAM

1GHz processor (2.4 GHz is recommended)

Application Pre-Requisites

If you are using Windows 11 (64 bit), 10, 8, 7 (32 bit or 64 bit), then please launch the tool as "Run as Administrator".
Microsoft .NET framework 4.5 and above

Supported Versions

Microsoft Windows
Microsoft Windows 11 (64 bit), 10, 8, 7 (32 bit or 64 bit) & Windows Server 2019, 2016, 2012 R2, 2008

Microsoft Outlook
Microsoft Outlook 2000, 2003, 2007, 2010(32/64 bit), 2013 (32/64 bit), 2016 (32/64-bit), 2019 (32/64-bit), 2021 (32/64-bit)




Electronic Delivery


Purchase the Offline OST Viewer Pro

OST Viewer Features Explained – Trial vs Pro vs Pro+

Features Free Viewer Pro Pro+
View OST File Emails with Attachments
Scan and View Corrupt Outlook OST File
Unlimited OST File Size
Dual File Scanning Option
Save into Portable Document Format
Advance Search Option
Multiple Naming Option
Export OST into Multiple Format
Supports Outlook 2021, 2019, 2016, 2013, 2010, 2007, 2003, etc.
Exchange Server 2019, 2016, 2013, 2010, 2007, 2003, etc.
Cost Free $69 $129
Common Queries By the Users

Commonly Asked Questions for better Understanding of the Tool

How we can browse for an OST File with attachments?

Read OST File

4 Step Process to View OST Files with Attachments:

  • Step-1: Download and Install OST File Viewer Utility
  • Step-2: Browse the OST File. Select Scan Mode:Quick & Advance
  • Step-3: Choose View Mode: Normal, Properties, Attachments
  • Step-4: Select Switch View: Horizontal & Vertical to Read OST File.
Yes, the OST file viewer tool is not dependent on the Outlook application or the Exchange Server environment and can work without them.
Yes, OST reader tool is free and can be used on unlimited machines as long as the usage falls within our fair usage policy.
Yes, the OST viewer tool is developed in a way that it supports all the versions of Windows operating system (11, 10, 8, & 7).
Yes, the OST reader software allows you to preview normal, damaged as well as password protected files.
Yes, the Microsoft OST viewer utility allows users to scan the corrupt OST file with Advanced Scanning option. After that, they can view and examine the corrupt OST file.
Yes, you can easily view and analyze OST file emails, contacts, calendars, tasks, and notes with the help of the Microsoft OST Viewer Utility.
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