Basics
Getting started
Install PST Viewer, open your first file and learn what “read-only” means.
Install PST Viewer
PST Viewer is free and open source – no subscription, no account, no ads and no in-app purchases. Download it from GitHub Releases for macOS, Windows, Linux or Android.
Step-by-step instructions for every platform, including what to do if macOS or Windows asks for confirmation on the first launch, are on the Installation page. For iPhone and iPad, see Mobile apps.
Open a file
- Launch PST Viewer.
- Choose Open File… or press ⌘O (Mac) or Ctrl+O (Windows, Linux).
- Select a PST, MSG, EML or MBOX file.
You can also drag a file onto the window. Recently opened files appear on the start screen so you can reopen them with a single click.
Even large PST files open quickly: the message list appears in about a second. PST Viewer then builds the full-text index in the background and shows its progress in the app.
Supported formats
| Format | What it is | Typical source |
|---|---|---|
| PST | Outlook data file with folders, emails, calendar items, contacts and tasks | Archives and exports from Outlook |
| MSG | Single Outlook item | Messages saved from Outlook |
| EML | Standard email file | Single emails saved from many mail clients |
| MBOX | Mailbox with many emails in one file | Gmail/Google Takeout, Apple Mail, Thunderbird |
Read-only – a promise
PST Viewer opens every file strictly read-only. Your PST, MSG, EML and MBOX files are never modified – not while searching, filtering or displaying them.
New files are only created in two cases:
- You export a message or save an attachment – always to a location you choose.
- You open an attachment in another app. For this, PST Viewer creates a read-only temporary copy that is deleted when you quit.