PST and OST Viewer for Outlook - 2026 Pricing, Features, Reviews & Alternatives

PST and OST Viewer for Outlook is a desktop PST viewer for Windows 10 and 11. It opens Outlook data files on any PC, so you can open a PST file without Outlook or even an Office license. The file is read in place and never modified, which keeps an archive usable as evidence and keeps read flags exactly as they were.

🔰 How to use it

1. Install the PST viewer and press Open.

2. Select a .pst or .ost file. It can sit on a local drive, a USB disk, a network share or in a restored backup folder.

3. Wait a moment while the folder tree fills in. Folders appear as they are read, so you can start browsing a 20 GB archive before the scan ends.

4. Click Inbox, Sent Items or any nested folder. The message list fills, and the number next to each folder tells you how many items it holds.

5. Type a sender, a subject word or a phrase from the body, and set a date range if you remember roughly when the email arrived.

6. Click the email to open it in the reading pane at full width, exactly as the sender formatted it.

7. Right-click to save that email as PDF, HTML, EML or MSG, to print it, or to copy its attachments to a folder.

👍 Features that matter in daily work

- Orphaned OST support. Outlook will not mount an .ost copied from another computer or left behind by a deleted Exchange or Microsoft 365 account. This OST viewer reads it as a plain file.

- A PST file viewer built for big archives. Messages load in batches, so long folders scroll instead of hanging.

- Search across subject, From, To and message body, combined with a date filter.

- Faithful rendering of HTML email, including inline images and formatted tables.

- Single-message export to four formats plus the standard Windows print dialog.

- Attachments saved under their original file names.

- 16 interface languages.

📂 How the PST viewer treats your file

The archive is opened for reading only. The app runs no repair pass, writes no index next to the file and leaves dates and read status alone, so the same PST can be handed to someone else afterwards in the state you received it. It also works fully offline and sends nothing anywhere, which keeps confidential mail out of third-party services.

✅ Who uses this PST viewer

- IT departments handling offboarding, where a former employee's mailbox survives only as a data file.

- Service desks that need one email out of an archive to close a ticket.

- Legal and HR reviewers who must keep correspondence on a local, offline machine.

- Consultants checking a backup or a migration result before signing off on it.

- Small offices with no Microsoft 365 subscription that inherited old Outlook archives.

❓ FAQ: questions people ask about PST files

What is in a PST file? A PST is Outlook's personal storage file. It holds a copy of mailbox folders and the items in them, often years of email. This PST viewer shows that folder tree and lets you read the messages inside it.

How do I open a PST file? In Outlook you attach it through File, Open & Export, which turns it into a live part of your mailbox. With this app you press Open and read it without touching any profile.

How do I open an OST file? Outlook only reads an .ost through the account that created it. Point PST and OST Viewer for Outlook at the file instead and its folders appear like those of a .pst.

Where is the PST file located? Outlook 2013 and later keep .pst files in Documents\Outlook Files by default. An .ost lives in %LOCALAPPDATA%\Microsoft\Outlook.

ℹ️ Free trial: every folder is visible with its first 20 messages, and the counters show the full size. A license lifts the limit.