Open PST files on your Mac. Nothing leaves it.

How to open a PST file on a Mac

1. Copy the file to your Mac. Outlook for Windows keeps .pst files in Documents\Outlook Files, and .ost files in %LOCALAPPDATA%\Microsoft\Outlook. Copy the file from the old PC, a USB drive or a backup into your Downloads folder.
2. Drop it on this page. Drag the .pst onto the box above, or click Choose PST file. Opening takes seconds, even for archives of several gigabytes, because nothing is copied or converted.
3. Pick a folder. Folders appear as they were in Outlook, with Inbox, Sent Items and your own archives. Messages list newest first; click one to read it with its attachments.
4. Search the whole archive. Type a name or subject to search every folder at once. Tick Addresses & message text to search email addresses, message bodies and attachment names too.
5. Keep what you need. Save any attachment, or a message as an .eml file that Apple Mail opens with a double-click. Print or save a message as a PDF from the message view.

Why Outlook for Mac won’t open your .pst

A .pst file is the archive format of Outlook for Windows. Outlook for Mac keeps mail in its own database and makes .olm files for its archives, so it can’t open a .pst like a document. At best it imports the whole file into a mailbox, and only in versions that still offer File › Import: that needs a working Outlook install, a licence and an account to import into.

Apple Mail reads mbox mailboxes, not .pst files, and Preview and Quick Look show nothing useful. Conversion tools usually ask you to upload the archive to a website, or to install software that wants access to your whole Mac. This viewer reads the .pst directly, in your browser, without importing or converting anything.

Your email stays on your Mac

Old archives hold years of private mail, so nothing here leaves your Mac. The browser reads the file a few hundred kilobytes at a time through its own file access, and the parsing happens inside this tab. The page’s Content Security Policy forbids network connections, no analytics, cookies or advertising scripts run, and there is no upload service to send a file to.

Email HTML is cleaned and shown in a sandbox with scripts and remote images blocked, so opening a decade-old newsletter doesn’t tell its sender you read it. Choosing Close file, or closing the tab, forgets the archive.

What it reads, and the limits

It reads Unicode .pst files from Outlook 2003 to Microsoft 365, older ANSI .pst files from Outlook 97–2002, and .ost offline files, including the compressed format of Outlook 2013 and later. Messages show their HTML, rich-text or plain-text body, recipients and attachments, and forwarded messages open in place. Calendar items, contacts and tasks appear as simple items with their text, not as a calendar or address book.

It can’t read files protected with Outlook’s “High encryption”, messages encrypted with S/MIME, or files damaged beyond their index. Searching names and subjects takes seconds even across 100,000 messages; searching message text reads every message, a few thousand a second on a recent Mac. Very large archives need memory for their index, so use a desktop browser for multi-gigabyte files.

Move the whole archive into Apple Mail: £9.99, once

Everything above is free. If you want the archive out of Outlook’s format for good, a one-off unlock adds bulk export, which runs on your Mac like the rest of the viewer:

• Apple Mail mailboxes: one .mbox per Outlook folder, ready for File › Import Mailboxes…
• Every message as an .eml file, in folders that mirror Outlook
• Every attachment, saved into folders by message date and subject

One payment of £9.99. No subscription and no account. It unlocks bulk export in the browser you buy it in.

Exports are ZIP files saved to your Mac. Very large archives are split into several ZIP files.

Try first: open your file, check the folders and messages you need are there, then decide.