PubRescue What is a .pst file?
A .pst file is an Outlook data file: a whole mailbox in one file, with folders such as Inbox and Sent Items, plus calendar items, contacts, tasks and notes. People get one when they export mail from Outlook, back up an old account, or inherit a mailbox from a former colleague.
An .ost file is similar. Outlook 2013 and later uses it to keep a local copy of mail from an Exchange or Microsoft 365 account.
How to open a .pst file
- Drop the .pst or .ost file onto the box at the top of this page, or click Choose files.
- Pick a folder. The Folder drop-down lists every folder in the file, indented like the tree in Outlook, with message counts.
- Browse the list. Messages are listed newest first. Click one to read it in the reading pane. On a phone, tap a message to open it and use the Back button to return to the list.
- Search. Type in the search box to filter the chosen folder by subject, sender and recipients. Tick Search message text too to look inside message bodies as well; it's slower, shows progress and has a Stop button.
- Save what you need. Tick messages, or use Select all, then choose Save selected as PDF, Export selected as .eml (ZIP) or Export as MBOX.
Which files it opens
- Old ANSI .pst files from Outlook 97 to 2002.
- Unicode .pst files from Outlook 2003 and later, including large ones.
- .ost files from Outlook 2013 and later.
The viewer checks what's inside the file, not just its name, so a renamed file still opens.
Big files open fast
A PST can be many gigabytes. The viewer doesn't load the whole thing. It reads only the pieces it needs for the folder or message you're looking at, so even a huge file opens in seconds and doesn't fill your computer's memory. A computer is more comfortable for big files, but phones work too.
Reading messages
Each message shows its subject, from, to, cc, date and body. HTML emails display in a locked-down frame where no scripts run. Pictures loaded from the internet are blocked until you click Load remote images, since they can tell the sender you opened the email. Messages stored as Outlook rich text are converted so you can read them.
Attachments can be downloaded one by one or with Download all (ZIP). Attached emails open in the same viewer. Use Save as .eml or Save as PDF for a single message.
Calendar items, contacts, tasks and notes appear in their folders with a small label, such as Calendar item or Contact, and open as simple items. They aren't shown as a full calendar or address book.
Where to find your .pst file
Outlook on Windows usually keeps .pst files in Documents\Outlook Files; older versions used AppData\Local\Microsoft\Outlook. .ost files are in AppData\Local\Microsoft\Outlook. To make a .pst from Outlook on Windows, choose File > Open & Export > Import/Export > Export to a file > Outlook Data File (.pst). Close Outlook before copying the file.
Your email stays on your computer
The viewer runs entirely in your browser. Your .pst file is read on your device and is never uploaded to our server or stored. Only this page and its scripts come from us. Searching, reading and exporting all happen on your computer.
Limits
- Encrypted (S/MIME) messages aren't decrypted.
- In a damaged file, the broken parts are skipped and the viewer tells you how many.
- .ost files from some setups may not open.
- Up to 500 messages per PDF; larger selections are offered in batches. See PST to PDF.
- A ZIP of .eml files holds up to 65,535 messages and 4 GB. Export in batches.
- MBOX export works one folder at a time; the folder structure isn't recreated in one export.
- Contacts and calendar items aren't converted to vCard or iCalendar files.