If you've ever exported your Gmail through Google Takeout, you've run into the same wall everyone does: you're handed a giant .mbox file, and almost nothing on your computer knows what to do with it. Double-clicking does nothing. Most "MBOX converter" tools want you to upload that file — your entire email history — to some server you know nothing about.
We built MBOX Viewer to fix that. It's live now at mbox.onescales.com.
What it does
MBOX Viewer opens your .mbox file directly in your browser — Gmail exports from Google Takeout, Thunderbird archives, Apple Mail exports, all of it. There's no install, no sign-up, and most importantly, no upload. The file never leaves your machine. Your browser reads it locally, a few kilobytes at a time, which is also how it handles archives that are 10GB, 50GB, or bigger without choking.
Once it's open, you get:
- A real inbox view — two-pane layout, search by sender or subject, filter by date range (a single year, a specific month, or any window you set).
- Exports that actually work with your other tools — CSV that drops straight into Google Sheets, Excel, or Numbers; PDF for printing or handing to a lawyer or accountant; EML files that re-import cleanly into Thunderbird, Outlook, or Apple Mail; or a smaller MBOX if you just need to split a huge export down to size.
- Attachment extraction — pull every attachment out of thousands of messages into one ZIP, filtered to just images or just PDFs if that's all you need.
Why we built it this way
We wanted a mailbox tool where "private" wasn't a claim you had to take on faith. There's no server component to MBOX Viewer at all — nothing to trust, nothing to leak, nothing stored. Open your browser's dev tools while you load a file and watch the Network tab: no mail data goes anywhere.
Getting started
- Go to Google Takeout, select Mail, and download your export.
- Unzip it — you'll get a
.mboxfile. - Drop it into mbox.onescales.com. Big files take a few minutes to index the first time; after that they open instantly.
Reading your mail and exporting a single message is free to try. If you want unlimited file size, bulk exports, and attachment extraction, a one-time $29 unlock covers it — no subscription.
Works best on desktop Chrome or Edge. Give it a try and let us know what you think.