SysTools OST Viewer Tool

View Corrupt or Orphan OST Files Without Email Client Dependency

(Average Rating 4.7 Based on 1967 Reviews)

Outlook OST Viewer





  • OST Viewer Allows to Previews OST Email With Attachments & Associated Items
  • Scans and Browses Corrupt or Orphan OST Files via Advanced Scan Mode
  • Sorts OST Emails by Attributes: From, To, Subject, Sent, and Size
  • Adds Multiple OST Files One by One and Previews Items in an In-built Viewer
  • Exchange Server Environment is Not Required to View OST Files Data
  • OST Email Viewer Provides Advance Scan Mode to Recover Deleted OST File Items
  • Reloads Saved Scan File and View OST File in Just a Few Seconds
  • OST Reader Maintains Read/Unread Message Status with All Features
  • Launch OST Viewer Software on Multiple Computers and Laptops Free of Cost
  • Supports OST Files of the Latest Microsoft Outlook 2021, 2019 and All Prior Versions
  • Download OST Viewer and Launch on:Windows 11 (64-bit), Windows 10, 8.1, 8, and 7
  • Upgrade to Pro Version to Avail Advanced Search and Export OST to PDF Options

Free Live Demo - SysTools OST Viewer Fully Secured Download Version

OST Viewer & Its Pro Versions

Different editions of OST Viewer offer a variety of features. Below is an extensive list of the features you can get with each edition:

OST Viewer

When you get this OST file viewer on your computer, you will be given access to a range of features.

  • View All OST Files
  • 8 different preview modes available to view the details of the OST file data.
  • Preview Emails, Contacts, Tasks, Calendar, Notes & Journal





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Pro Edition

If you want to access additional features, upgrading to the Pro Version of Outlook OST Viewer is recommended.

Features of OST Viewer

  • Search for OST files either within a specific drive or across all drives.
  • Support Various Files in Batch
  • Remove SMIME / OpenPGP Encryption
  • Advanced Search allows users to find specific data more effectively.
  • Convert to PDF with numerous, custom settings.
  • Print OST Emails

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Pro+ Edition

Outlook OST Viewer Pro Plus, the most advanced version, comes with the best features:

Features of OST Viewer Pro

  • Export all data into PST format
  • Export emails into MBOX format
  • Export all items into individual MSG file
  • Export only emails in the form of EML or EMLX




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Multiple OST Preview Modes

Multiple Preview Modes to View OST Files

With SysTools OST Viewer Pro, one can view OST files in different preview modes provided by the software. Forensic Investigators can also perform an in-depth analysis of OST emails via the various preview modes provided by the software. Moreover, the utility is capable to work with OST files of different Outlook versions without any compatibility issue.

Preview Modes Provided By OST Viewer

  • Normal Mail View
  • Hex View
  • Properties View
  • Message Header View
  • MIME View
  • HTML View
  • RTF View
  • Attachments View

Support OST File of Outlook Version

  • Microsoft Outlook 2021
  • Microsoft Outlook 2019
  • Microsoft Outlook 2016
  • Microsoft Outlook 2013
  • Microsoft Outlook 2010
  • Microsoft Outlook 2007
  • Microsoft Outlook 2003
  • Microsoft Outlook 2002
  • Microsoft Outlook 2000

OST Viewer Pro

Robust Search and Export Functionalities

Sometimes, the user needs to search for a particular OST email among various OST files. With the OST Viewer software developed by SysTools, the user can easily search for a specific OST email using the Advanced Search feature and also save the search results into Portable Document Format.

  • Advanced Search: You can easily search for a particular OST email from among tons of OST files in a simplified way with the help of the Advanced Search option. You can make your search results more specific by applying the various filters and operators provided by the OST Viewer tool.
  • Export to Portable Document Format: In some cases, the user needs to save OST files into Portable Document Format. For instance, any sort of evidence carved out of an OST file need to be presented in courts in the Portable Document Format. This tool allows Forensic Investigators to easily export OST emails in the required format while keeping all the document formatting intact.

View Different Data Items Associated With OST Using SysTools OST Viewer

Normal Mail View View OST file emails along with attributes such as:
  • Path
  • From
  • To
  • Cc
  • Bcc
  • Subject
  • Attachments Message Body
  • Date
  • Time
Attachments View
  • View attachments associated with OST files
  • Preview different types of attachments such as images, text, DOCX, and charts
  • Play audio and video files present in the attachments directly from the software interface
Email Functionalities Show status of OST emails:
  • Read Status
  • Unread Status
Sort OST emails according to attributes such as:
  • From
  • To
  • Subject
  • Send
  • Received
  • Size (KB)
Calendars Details View OST files calendars along with the information and attributes such as:
  • Path
  • Subject
  • Location
  • Start Time
  • End Time
  • Recurrence
  • Attachments with Contacts
Sort calendars associated with OST file according to:
  • Subject
  • Location
  • Start
  • End
  • Categories
Personal Details The software permits the user to view OST files contacts along with the personal details such as:
  • Name
  • Nick Name
  • Birth Date
  • Spouse
  • Anniversary
Contact Details One can view different contact details of OST contacts:
  • Primary Phone
  • Mobile Phone
  • Pager
  • Home
  • Business
Address Details The software allows the user to view address details such as:
  • Home Address
  • Business Address
  • Other
Email Address One can easily view the email address associated OST contacts.
Sort Contacts The tool permits the user to sort emails according to:
  • Full Name
  • Company
  • File As
  • Business Phone
  • Business Fax
  • Home Phone
  • Mobile Phone
  • Categories
Tasks Details One can also view the attributes associated with the OST files tasks such as:
  • Subject
  • Start Date
  • Status
  • Due Date
  • Priority
  • Complete
  • Reminder
  • Owner
  • Recurrence
  • Attachments related to OST tasks
Sort Tasks The user can easily sort tasks according to:
  • Task Subject
  • Status
  • Due Date
  • Categories
Notes Details The user can view OST files notes along with the details such as:
  • Subject
  • Created
  • Categories
Journals Details The tool allows the user to view information related to OST Journals:
  • Subject
  • Category
  • Entry Type
  • Start
  • Attachments
  • Company
  • Duration
Sort Journals One can easily sort Journals associated with OST files according to:
  • Subject
  • Start
  • Duration(min)

Prime Features of SysTools OST Viewer

Error Free OST Viewer Tool to View Corrupted OST Files

View OST File without Outlook

Preview Multiple OST Files

With free OST Viewer software, you can view OST files, emails, contacts, calendars, etc. The OST file viewer software generates a preview of all the OST file messages with attributes such as From, Subject, To, Sent, Received date and Size in bytes. One can also view details associated with an OST email message such as path, subject, cc, to, and bcc.

explore OST File with Attachments

View Email Attachments

One can view the attachments associated with OST emails directly from the OST Viewer software’s dashboard. The user can view different types of attachments such as images, documents, and files via the tool. Moreover, the software permits the user to play any audio or video files embedded into the attachment from the software interface.

Scan & Save OST File

Advanced Scan and Save Scan Mode

Outlook OST Folder Viewer tool also allows users to view orphan as well as corrupt OST files. If you need to view a corrupt OST file, then just select the Advanced Scan option to scan the OST file and eliminate the corruption. After the scanning process, the Save Scan Mode permits you to save the healthy OST file in the software interface. You can load the saved OST file just by clicking the Load Scan option.

No Pre-Requisites

No Pre-Requirements

One can easily view OST files using the OST Email Viewer software without the help of any email client. Moreover, there is no requirement of Exchange Server environment to view OST files. Free OST reader is a standalone utility, which allows users to view and explore OST files seamlessly along with all the data items. Standalone OST Viewer Tool to open OST files without Outlook 2021, 2019, 2016, and below versions.

view OST File Contacts

OST Contacts Viewer

Outlook OST Viewer software provides the preview of all the contacts associated with the OST file along with different attributes. The user can easily view personal details, contact details, address details, emails address associated with contacts, etc. OST explorer software also allows the user to sort OST contacts according to various attributes such as From, Company, File As, Business Phone, Home Phone, Mobile Phone, and Categories.

View OST File Calendar

OST Calendar Viewer

The free OST Viewer tool also permits the user to view calendars related to OST files directly from the software’s dashboard. The user can view calendar details such as path, location, start time, end time, and recurrence. Additionally, one can also sort OST calendar according to Subject, Location, Start, End, and Categories. Preview OST file calendar items in Windows OS 11, 10, 8, 7, Server 2019, 2016, 2012, and 2008.

Sort OST File

Sort OST File Data By Attributes

The Outlook OST Folder Viewer software allows the user to sort OST emails, contacts, calendar, notes, etc., according to particular attributes. These attributes vary according to OST file data items. These attributes include: From, Company, Location, Subject, Category, Size, Home Phone, File As, To, Sent, Received, etc.

OST Optimized View

Optimized OST Viewing

The OST Reader tool allows the user to view OST file items in an optimized way without the occurrence of any error. The software also provides an option to change the location of its Temp folder from the installation drive (C drive) to any other drive. This helps to reduce the main memory consumption.

Upgrade to SysTools OST Viewer Pro to Avail Advanced Features

Preview Email in Multiple Modes

Preview Emails in Different Styles

With OST Viewer Pro, the user can preview OST emails in different file formats such as Normal Mail View, Hex View, Property View, Message Header View, MIME View Attachments View, and RTF View.

Sort Email by Property

Sort Email via Property

Once the emails present in the OST file get listed, you can sort or arrange the emails on the basis of their attributes such as From, To, Received Date, Sent Date, and Size in KB using the Outlook OST viewer pro application.

OST File Search

Advanced Search OST File

OST Viewer Pro grants the advanced searching feature to find a specific email by typing a matching keyword or term. The user can apply various filters such as To, Bcc, and CC and filter operators like AND/OR to perform deep searching of messages of an OST file.

Export OST Files

Export Data in Portable Format

The user can also save emails in Portable Document Format via OST Viewer Pro utility. The software also allows you to export batch emails along with their attachments as well as only some OST files through the selective export process.

Date Filter

Date Filter Option

Use the Date Filter option, provides by the OST Viewer Pro Tool to export OST emails according to a particular date range. To apply the date filter, you need to select the desired date range in ‘To’ and ‘From’ fields.

Selective Export

Save Selective Files or Folders

Users can easily check or uncheck the OST files or folders which they want to export into Portable Document Format. This will save the user’s time by exporting only the required OST files or folders.

Naming Option

Set Naming Pattern

One can easily use various combinations of date, year, month as well as auto incremental options to save the resultant file. By default, the files will get saved by the line of the subject. The software offers a list of file naming patterns for you to choose from as per your requirement.

Create New Folder

Make New Folder to Save File

SysTools OST File Viewer Pro utility prompts users to choose the desired location for saving the converted OST files. The tool also allows users to create a new folder from the software panel to save the Portable Document Format files directly into it.

OST Viewer Software Specifications

Free Download OST Reader Software

Software Download

Size: 18.1 MB

Version: 5.0

MD5: 7920bd60326278c1bd912f4146f604d7

Software Limitations

Free version of SysTools OST Viewer Tool only lets you preview all Outlook OST Emails, Contacts, Calendar, Notes, Task, Journal Items.

System Specifications

Hard Disk Space
100 MB of free hard disk space required

2 GB is recommended

Intel® Core™ 2 Duo CPU E4600 @ 2.40GHz 2.39GHz

Operating System

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


If you are using Windows 11 (64-bit), Windows 10, 8, 7 (32 bit or 64 bit) & Windows Server 2019, 2016, 2012 R2, 2008, then please launch the tool as "Run as Administrator".
Microsoft .NET framework 4.5 and above

Supported Editions

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)



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Upgrade to OST Viewer Pro Version

Upgrade to Outlook OST Viewer Pro for Advance Search & Export Option

Features Viewer PRO PRO +
Add OST File
Auto Scan Mode
Open Outlook BAK File
Preview OST Files
View Emails with Attachments
Free Installation on Multiple Computers
Advance Search Options
Naming Option
Save to Portable Document Format
Export OST to PST, EML, MSG
Split Outlook Data File
Cost FREE $69 $129
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Awards & Ratings of SysTools OST Viewer Software

2023 Highly Rated & Most Popular Outlook OST Viewer Tool

Awards & Reviews

MVP & Expert Reviews

Frequently Asked Questions

Listed Commonly Asked Questions and Answers

How can I view an OST file without the Exchange Server connectivity?

Free OST Viewer

Perform the following steps to view an OST file without connecting to the Exchange Server:

  • Step-1: Download and Install Outlook OST Viewer Tool
  • Step-2: Browse the OST File with Advance Scan Option
  • Step-3: Horizontal or Vertical Mode to View OST File with Attachments
  • Step-4: Upgrade to Pro for Search, Print & Export Options

Yes, the OST Viewer tool is compatible with Windows 11, 10 machine and all its previous versions. You can view an OST file easily with the help of the OST file opener.

There is no limitation on the size of the OST file or number of emails that the OST file explorer software can process.

OST Viewer is absolutely free of cost with limited options. For advance options like Export to Portable Document Format or Advance Search, you need to upgrade to OST Viewer Pro.

Yes, you can view an orphan OST file using OST Viewer. No application or Server environment is required to view OST files by the OST file browser.

Yes, the OST explorer software allows you to view even corrupted file contents, irrespective of the type or level of corruption. OST file viewer tool has two modes of scanning: Quick and Advance. The Quick mode is the default mode, which is used if there is minor corruption in the OST file. In case the file is highly corrupted or you are still not getting the entire set of data items, then use the Advance option for scanning. This mode scans every sector of the file thoroughly and is used to retrieve the contents of highly-corrupted files.

Yes, the free OST File Reader can view OST files even without having Outlook and Exchange Server environment. OST reader software is completely independent of Outlook or Exchange Server to view OST files.

No, it is not possible to save the previewed data using the free OST Viewer tool. However, you can save all the data into any desired file format using OST Converter.

Yes, you can view OST files via the OST Reader software without facing any data loss or security issues.

Yes, one can easily view the attachments associated with an OST file by using the OST Reader Attachments View Mode.

What Customers Are Saying

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