About OLMExport
What this is
OLMExport is a free tool that converts the .olm archive Outlook for Mac writes into formats other software can read: MBOX, EML, PDF, searchable HTML, CSV, vCard and ICS. It runs as a web page, in your own browser, with no account and no upload.
Why it exists
Legacy Outlook for Mac loses support in October 2026, and its archive format is documented nowhere. Everything that ranks for “olm to mbox” or “olm to pdf” today is either a Windows program that costs $29 to $49 and stops after a demo, or an online converter that wants you to upload your entire mailbox to a stranger’s server. Neither is a reasonable answer for an HR file, a legal copy or a colleague’s archive handed over at offboarding.
How it works
An .olm is a ZIP container holding one XML document per message plus the attachments as separate files. The page opens the container in the browser, reads entries one at a time so a multi-gigabyte archive does not have to fit in memory, and writes the output on your machine. Timestamps are read as UTC, which is how Outlook stores them even though it omits the time zone marker, the detail most converters get wrong.
Who makes it
OLMExport is built and maintained by a small independent team that publishes a handful of single-purpose file tools. It is not affiliated with, endorsed by or connected to Microsoft. Outlook is a trademark of Microsoft Corporation.
How it is funded
Ads on the pages. There is no paid tier in this version, no trial limit and no upsell; the whole converter is free to use. If that changes, the free conversions on this page stay free.
Limitations we admit to
- The format is undocumented, so contacts and calendar handling is best-effort.
- Notes and tasks are skipped in this version.
- PST is not produced: it is a binary database, not a container of messages, and a subtly wrong PST is worse than none. See the OLM to PST page for the route that works.
Contact
Questions, bug reports or a format request: see the contact page.