Free OST File Viewer without Outlook

Sometimes during your work, you encounter situations where you need to view letters saved to your hard drive through Microsoft Outlook, recover damaged or corrupted .pst files along with their mail attachments. And sometimes, you even try to save data in a more convenient format and it’s just not possible through MS Outlook. Only a special tool called the OST viewer can do this for you.

Today, I will be talking about the free OST Viewer of Recovery Toolbox for Outlook I will take you through the functionality of the program and how to install its offline version. I will also compare the viewer to other viewers so you can get an idea of just how effective the OST Viewer is.

Program Features

The developer of Recovery Toolbox has created an Outlook Viewer that allows the user of any PC no matter the OS gain full access to messages that were once opened in Microsoft’s mail client whether the files became damaged or inaccessible for any reason at all.

Here are some of the features of the tool:

  1. It opens OST files regardless of their state, including password-protected.
  2. Shows all contents of MS Outlook folders.
  3. Displays a directory tree with saved OST and PST files.
  4. Finds email addresses, reminding the user of the contacts of those with whom he corresponded.
  5. Recovers attached (attached) files from letters.
  6. Recovers journals, calendars, tasks, etc.
  7. “Resurrects” deleted PST and OST files.
  8. Allows you to resave .ost files with other extensions, thereby making them available not only without Outlook but also without a viewer. Subsequently, they can be sent to others or uploaded to the “cloud” and then opened from any device.
  9. Exports data from *.OST files to MSG format, which can be imported into most popular email clients.

Note: Upon completion of data recovery, the program automatically generates a clear report on the number of items “returned” to the user, their total volume in megabytes or gigabytes.

It also restores the files along with the addresses of people to who you need to send letters again; it also restores attached files including documents, images, and links to important web pages.

It also restores calendars with a very helpful task you do a lot of time management and planning. You can compare your previous work with the current one using the calendar and correct your mistakes thereby increasing personal efficiency.

How the Viewer Works

Let’s take a step by step view of how the viewer works:

Step 1.

Find the file to be processed.

Step 2

Choose what the tool should do for you:

  • Recovery mode – if you need to restore the content.
  • Converter mode – to export the contents of the OST file to PST.
  • Scan for deleted data – to find the item that was deleted.

Note: If the .ost file has been completely removed or deleted from the hard disk, it is impossible to restore the file using the viewer. Firstly, you have to get it back on the disk using a tool made for the restoration of deleted files. Here is a link to a suitable  one freeware tool:  

Step 3

Once the items have been restored, go ahead and select the ones that you might need in the future to save them.

Step 4

Select the directory where our Free OST Viewer should write the saved files.

Step 5

We command how to re-save the saved goods – leave it with the .pst extension or write it down with other files.

How to install the program

Here’s how to install the tool on a computer that has the Windows Operating System:

  1. Open the developer’s website page in the browser
  2. Save the file (installation) to your computer.
  3. Open the file, click “Run”.
  4. Install the Viewer following the prompts.

Tip: Pay attention to the additional options that the installer will offer. Agree only to those about whom you have an idea, why they are needed, and what they give. Ignore the rest and politely uncheck the boxes.


Online version

Now if your computer does not run on the Windows OS, there is no need to worry as you can still use the OST viewer through the online version. This is one of the advantages of using the Viewer as you can use it without installing it on your computer. The tool is available at

Using the web version, you can restore the .ost file and save it on your PC with the same .PST extension.

Just follow the steps below:

•         Load the file by pressing a special button.

•         Drive-in your email address into the field below.

•         Drive in the characters from the captcha into the next field, so that the program is finally convinced that “I’m not a robot”.

•         Click “Next”.

•         We are waiting for the completion of the “restoration”.

•         Download the corrected PST file to a folder.

Note: The new file is in Unicode format and compatible with MS Outlook 2016.

Advantages of Recovery Toolbox for Outlook

There are a lot of advantages to using this program:

  1. The full version of the program for Windows finds, opens, restores all contents of Outlook folders.
  2. It can open and restore large files, unlike other viewers. It has no limit to the amount of data that can be restored so long the computer has the RAM for it.
  3. The program successfully works with data that has been attacked by ransomware “viruses” – it opens, “cures”, makes the information available again.

If you need to restore a file larger than 4 Gigabytes, the tool needs a computer with a Windows 64-bit operating system and 64-bit MS Outlook installed. If Windows is 32-bit, the viewer still does not have enough RAM for a size larger than 4 Gigabytes.

When restoring OST files keep in mind that the “restored” file will be compatible with the version of Microsoft Outlook installed on the PC where the “restoration” was performed. You won’t be able to import it into another version of Outlook.


Recovery Toolbox for Outlook has every right to claim the status of the best Free OST Viewer out there. It gives the user much more flexibility in comparison to other free software for working with PST and OST files.

The program page on the developer’s site contains answers to the most frequent questions that arise when using the viewer. The same resource introduces other products of the company.

The online version allows you to restore OST data without installing programs on your computer, after which the file can be converted without leaving the browser to another, more convenient format.

Now all the information saved in MS Outlook becomes available again. I hope this was helpful to you!