OLM viewer

The file you get

Nothing, unless you want it. The viewer reads the archive in the page: folder list on the left, message list in the middle, the message you picked on the right, with a search box over everything. When you do want a copy, every export on this site is a click away with the file already loaded.

Steps

1. Get the .olm out of Outlook for Mac first: Tools tab → Export, tick what you want, Continue, save the file. If Export is greyed out you are in the new Outlook; switch the New Outlook toggle off, top right, and it comes back.
2. Drop the .olm on this page. It is read by JavaScript in your browser tab; the file never leaves your machine.
3. Click a folder to list its messages, and a message to read it. Attachments open or download from the message.
4. Search by sender, subject or any phrase in the body. Sort by date or sender.
5. If you need to keep it, pick an export, MBOX for a mail app, PDF for a record, HTML to keep the whole thing readable.

What carries over

• The folder tree exactly as Outlook stored it
• Message headers, HTML body and inline images
• Attachments, opened or saved from the message
• Contacts and calendar entries from the archive, in their own tabs
• Full-text search across every folder, running locally

Good to know

• Reading a very large archive takes a moment while the index is built. Nothing is uploaded during that time; the work happens on your processor.
• Outlook writes times in UTC but leaves the time zone off the timestamp. Every date here is read as UTC, so nothing shifts by your offset, a common fault in other converters.
• 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.
• The viewer shows what is in the archive. It cannot recover a corrupt or partially written .olm; if the zip container itself is damaged, no reader on this page or anywhere else will get past it.
• 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.