What is an MBOX file?

MBOX is a plain text format for storing a whole mailbox in a single file. Gmail's "Takeout" export, Thunderbird, Apple Mail, and many other mail clients all use it to bundle every message in a folder, headers and attachments included, into one file. That makes MBOX great for backups and migrations, but a pain when you just want to pull the attachments back out, since they're buried inside encoded email bodies rather than sitting as separate files.

Tool description

This tool reads an MBOX file entirely in your browser and pulls out every attachment from every message. It splits the file into individual emails, parses each one, and collects the attachments into a browsable file tree organized by message subject. You can download attachments one at a time or grab everything at once as a ZIP.

Features

  • Runs entirely in the browser - your mailbox never leaves your device
  • Organizes attachments by message, using the subject line as a folder name
  • One click download of every attachment as a single ZIP file

Tips

  • Very large MBOX files depend on your browser's available memory. If extraction fails on a huge export, try Firefox, which has been confirmed to handle files up to 1 GB.
  • Messages that fail to parse are skipped and counted, rather than stopping the whole extraction.