Free MBOX viewer
Open a .mbox mailbox — like a Gmail export from Google Takeout — and browse, search, and read every message. Extract any email as a standalone .eml file.
- 100% in your browser — never uploaded
- Streams multi-GB Takeout files
- Free, no signup
No mbox file handy?
How it works
Built for Google Takeout exports
01
Export from Gmail
At takeout.google.com, select only Mail and export. You'll get one big .mbox file with every message.
02
Drop it here
The viewer streams through the file locally and builds a searchable index — even multi-gigabyte exports never leave your device.
03
Read & extract
Search, open any message with its attachments, and download individual emails as standard .eml files.
FAQ
Is my mailbox uploaded when I open it here?
No. The file is scanned by JavaScript running locally in your browser and never leaves your device. Only a lightweight index (subject, sender, date, byte positions) is kept in memory — messages are read from the file on demand when you click them.
Can it handle a large Google Takeout export?
Yes — the viewer streams through the file instead of loading it all into memory, so multi-gigabyte “All mail Including Spam and Trash.mbox” exports work. Scanning speed depends on your machine; expect a few seconds per gigabyte.
How do I get an mbox file from Gmail?
Go to Google Takeout (takeout.google.com), deselect everything except Mail, and export. Google delivers a .mbox file containing every message. Thunderbird and Apple Mail can also export folders as mbox.
Can I extract a single email from the mbox?
Yes — open any message and click “Download .eml”. That saves the selected message as a standard .eml file you can open in any mail client, share, or archive individually.
What's the difference between mbox and .eml?
An .eml file is one message; an mbox file is an entire mailbox concatenated into a single file, message after message. mbox is fine for bulk export but clumsy for daily use — you can't search, open, or share one email without special software. That's why per-message .eml archives are the better long-term format.
Got a single .eml file instead? Open it in our free EML viewer, or read up on the .eml format. Haven't run the export yet? Our guide to backing up Gmail walks through Google Takeout step by step — and if your .mbox came out of Apple Mail, see how to back up iCloud email. Opening a file straight out of a Thunderbird profile? Our guide to backing up Thunderbird explains where those files live and how to export them properly.