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OLMExport

Open an .olm file without Outlook

An .olm is the archive Outlook for Mac writes, and Outlook for Mac is the only program that imports it. Which is awkward if you are on Windows, if the Mac has gone back to IT, or if the licence expired, the file is right there and nothing opens it. It is not encrypted and it is not proprietary in any useful sense: it is a ZIP full of XML. Drop it below and read it.

The file you get

Whichever you need. Read it here with no download at all; or convert it to MBOX for Apple Mail or Thunderbird, EML for single messages, PDF for a record copy, or one searchable HTML file to keep.

Steps

  1. Find the file. It is wherever the person who made it saved it, often Downloads or Documents, with a name like Outlook for Mac Archive.olm.
  2. Drop the .olm on this page. It is read by JavaScript in your browser tab; the file never leaves your machine.
  3. Read the folder tree and the messages in the page. Search across the whole archive if you are looking for something specific.
  4. If you need the mail somewhere permanent, pick a destination: MBOX for a mail app, EML for individual messages, PDF to print, HTML to keep it searchable.

What carries over

  • Mail from every folder in the archive, with headers, bodies and attachments
  • Contacts and calendar entries, if they were ticked when the archive was made
  • The original folder structure
  • Everything readable on Windows, Linux or ChromeOS, the archive is from a Mac, the reader is a web page

Good to know

  • Renaming .olm to .zip and unzipping it does let you see inside, but you get thousands of XML files with names like message_00012.xml in folders called com.microsoft.__Messages. It is not readable mail. That is the job this page does.
  • An .olm is not a mailbox you can connect to. It is a point-in-time export, so it holds what was in Outlook the day it was made and nothing after that.
  • Microsoft has never published the .olm format. Mail, attachments, contacts and calendar entries are read from the XML Outlook writes; unusual items (notes, tasks, journal entries) are skipped in this version.
  • Archives over about 2 GB are written straight to disk in Chrome and Edge. Safari and Firefox assemble the download in memory, so on a very large archive use Chrome, or convert one folder at a time.
  • A damaged archive cannot be repaired here. If the zip container itself is broken, ask for a fresh export.

Questions

Can I open an .olm on Windows?
Not with Outlook for Windows, it reads .pst, not .olm. Open it on this page, which runs in the browser you already have. If you need it inside Outlook for Windows afterwards, follow the OLM to PST route.
Is there a free OLM viewer that does not upload my file?
This one. The page is static and the parsing runs in your tab, so the archive never leaves the machine. Most of the other free viewers are Windows programs that charge as soon as you try to export anything, and the online ones upload.
Do I need the password from the Mac it came from?
No. An .olm is not password-protected. If Outlook asked for a password when the archive was made, that was the account, not the file.
Can Apple Mail open it directly?
No. Apple Mail imports mbox, so convert first; the Apple Mail page has the exact import steps.
What if my file is a .pst and not an .olm?
Different format, PST is the Windows Outlook file. This tool does not read it.

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