How to Open PST File Without Outlook (Free, in Your Browser)
A PST file is an Outlook Data File: a backup or archive of email, contacts and calendar items. With Outlook for Windows you open it from File > Open & Export > Open Outlook Data File. Without Outlook, the free viewer below opens the PST right in your browser: browse the folders, read every message, download attachments and save emails as .eml for Gmail, Apple Mail or Thunderbird. The file is read on your device and never uploaded.
Choose what you need
Open PST File Online: Browse Folders & Read Emails (Free)
Drop a .pst file below. The viewer reads the Outlook data file directly in your browser and shows its folder tree with item counts. Pick a folder to list the messages, then open any message to read it, see recipients and headers, download attachments, or save it as .eml for another mail app. ANSI and Unicode PST files from every Outlook version are supported.
Good to know: large PSTs (several GB) open too, because only the parts you look at are read. The file isn't changed or uploaded.
🔒 Nothing is uploaded — your mailbox never leaves this deviceOn this page
What is a PST file?
A PST (Personal Storage Table) file is Microsoft Outlook's data file for storing a copy of messages, calendar events, contacts and other items on your computer. Outlook creates PST files when you archive old mail, when you export a mailbox (File > Open & Export > Import/Export), and for POP email accounts, whose mail lives only in the PST.
Inside, a PST is a database: folders, messages and attachments are stored as nodes in B-trees, and the data can be scrambled with Outlook's "compressible encryption". That's why a text editor or a ZIP tool can't open it, and why you need Outlook or a dedicated viewer such as the one above.
| PST format | Created by | Size limit |
|---|---|---|
| ANSI | Outlook 97–2002 | 2 GB |
| Unicode | Outlook 2003 and later | 50 GB by default (Outlook 2010 and later) |
| Full name | Outlook Personal Storage Table (Outlook Data File) |
|---|---|
| Contains | Email, attachments, calendar, contacts, tasks, notes |
| Default location | Documents\Outlook Files (Windows) |
| Related | .ost (offline cache), .msg (single item), .eml (standard email) |
How to open a PST file: quick answer
| Situation | Best option |
|---|---|
| You have classic Outlook for Windows | File > Open & Export > Open Outlook Data File |
| You use new Outlook for Windows | Settings > Files > Outlook Data Files > Add file (needs classic Outlook installed too) |
| Mac with legacy Outlook | File > Import > Outlook for Windows archive file (.pst) |
| No Outlook, any device | The viewer at the top of this page |
| Move mail to Gmail or Apple Mail | Viewer above > Save as .eml, then drag into the mail app |
Open a PST in Outlook for Windows
Classic Outlook (Microsoft 365, 2021, 2019, 2016)
- Choose File > Open & Export > Open Outlook Data File.
- Select the .pst file and click OK. It appears as a separate folder group in the folder pane, below your mailbox.
- To copy everything into your mailbox instead, use File > Open & Export > Import/Export > Import from another program or file > Outlook Data File (.pst).
New Outlook for Windows
Go to Settings > Files > Outlook Data Files, select Add file and choose the .pst. Microsoft says this requires classic Outlook to be installed too (same 32-bit or 64-bit version), a Microsoft 365 subscription, and it isn't available on the ARM version. If any of that doesn't apply to you, use the browser viewer above.
Open a PST on a Mac
Apple Mail can't read PST files. Your options:
- Legacy Outlook for Mac: File > Import, choose Outlook for Windows archive file (.pst) and pick the file; the items appear under On My Computer. Microsoft's instructions apply to legacy Outlook for Mac, not the new Outlook for Mac.
- Any browser on the Mac: open the PST with the viewer on this page, read the messages and save the ones you need as .eml. Double-clicking an .eml opens it in Apple Mail, and you can drag several into a mailbox.
Move PST email to Gmail, Apple Mail or Thunderbird
Gmail and most mail apps can't import a PST directly, but all of them understand .eml files:
- Open the PST in the viewer above and select a message.
- Click Save as .eml. The .eml keeps the sender, recipients, date, body and attachments.
- Open it in Apple Mail, Thunderbird or Windows Mail, or drag it into a folder of an IMAP account (such as Gmail set up in Thunderbird or Apple Mail) to upload it to the server.
For a whole mailbox, Google Workspace offers a free migration tool for Outlook; with Outlook installed you can also add the Gmail account to Outlook and drag folders from the PST into it.
Repair a PST that won't open
If Outlook says the file "is not an Outlook data file" or has errors, use Microsoft's Inbox Repair Tool (scanpst.exe), included with Outlook:
- Close Outlook and make a copy of the PST; repair the copy.
- Run SCANPST.EXE, usually in
C:\Program Files\Microsoft Office\root\Office16(Microsoft 365, 2021, 2019, 2016). - Browse to the PST, click Start, then Repair. Run it again until it reports no errors.
- Open the repaired file in Outlook; recovered items may be in a Recovered Personal Folders or Lost and Found folder.
Before repairing, try the viewer above: it reads the file without changing it and may show folders that Outlook refuses to open. It also tells you if the file is truncated (shorter than its header says), which usually means an incomplete copy rather than damage.
Other PST problems and fixes
"The file is in use" or "cannot be accessed"
Outlook still has it open, or it's on a network drive or USB stick. Close Outlook (check Task Manager), copy the PST to a local folder and open the copy.
The PST is huge and Outlook is slow
Large PSTs (tens of GB) slow Outlook down and are more likely to get damaged. Split them by year with Archive, or keep old ones closed and open them only when needed.
The PST has a password
Outlook asks for it every time you open the file. Microsoft doesn't offer a way to recover a forgotten PST password, so keep it with your other passwords.
It's an OST, not a PST
OST files are caches of server mailboxes and can't be opened with "Open Outlook Data File". See our OST guide.
Sources and technical references
- Open and find items in an Outlook Data File (.pst), classic and new Outlook — Microsoft Support
- Import a .pst file into Outlook for Mac — Microsoft Support
- Repair Outlook Data Files (.pst and .ost) — Microsoft Support
- [MS-PST]: Outlook Personal Folders (.pst) File Format — Microsoft Learn
- pst-extractor test data (Enron sample PST) — GitHub
Frequently asked questions
How do I open a PST file without Outlook?
Drop it into the free viewer on this page. It reads the PST in your browser, shows the folders, and lets you read every message, download attachments and save emails as .eml for Gmail, Apple Mail or Thunderbird. The file isn't uploaded.
How do I open a PST file in Outlook?
In classic Outlook choose File > Open & Export > Open Outlook Data File and select the .pst. In new Outlook for Windows go to Settings > Files > Outlook Data Files > Add file; Microsoft says classic Outlook must also be installed.
Can I open a PST file on a Mac?
Apple Mail can't read PST files. Legacy Outlook for Mac imports them with File > Import > Outlook for Windows archive file. Otherwise use the browser viewer on this page and save messages as .eml for Apple Mail.
How do I import a PST into Gmail?
Gmail doesn't import PST files directly. Open the PST in the viewer here and save messages as .eml, then move them into Gmail through an IMAP mail app, or use Google's migration tool for Outlook with a Workspace account.
How do I repair a corrupted PST file?
Close Outlook, copy the PST, and run Microsoft's Inbox Repair Tool (SCANPST.EXE) on the copy until it reports no errors. The viewer on this page can also read many damaged files without changing them.
What's the difference between PST and OST?
A PST is a standalone data file used for archives, exports and POP accounts. An OST is an offline cache of a server mailbox that only works with its own Outlook profile; the server holds the master copy.
How big can a PST file be?
Unicode PST files created by Outlook 2010 and later have a default limit of 50 GB; old ANSI PST files from Outlook 2002 and earlier are limited to 2 GB. Very large files slow Outlook down.
Is it safe to open a PST file online?
Only with a viewer that doesn't upload the file, because a PST holds your whole mailbox. The viewer on this page reads it entirely in your browser and blocks remote images in emails.
Last updated .