Guide · Mail archives
Open an MBOX file in your browser
Downloaded your mail from Google Takeout, or exported a mailbox from Thunderbird or Apple Mail, and got one huge .mbox file? MSGView lists every message in it, lets you search and open them, and shows the Gmail labels. The archive is read in pieces inside your browser and never uploaded.
Open an MBOX file in 3 steps
- Open MSGViewGo to msgview.app in a desktop browser. Nothing to install, no account.
- Drop the .mbox fileDrag the archive onto the page. MSGView starts listing messages straight away and keeps counting while it reads the rest of the file.
- Search and openSearch by subject, sender or Gmail label. Click a message to read it with its attachments, then go back to the list.
What is an MBOX file?
MBOX is a plain format that stores many emails one after another in a single file. Gmail (through Google Takeout), Thunderbird and Apple Mail use it for exports and archives.
Large archives
A Takeout archive can be many gigabytes. MSGView never loads the whole file at once: it reads it in pieces, keeps a small list of the messages, and reads one message only when you open it. While it is still reading, the count and the search say how much has been read so far.
Private by design
Your archive is your whole mailbox. It is opened in your browser and never sent to a server. You can check this in the Network tab of your browser's developer tools.
FAQ
How do I open a Google Takeout .mbox file?
Unzip the Takeout download, then drop the .mbox file on msgview.app. You see every message, with its Gmail labels.
Does it work with Thunderbird mail?
Yes. Thunderbird folders are MBOX files. Messages Thunderbird marked as deleted but has not removed yet are shown and labelled as deleted.
Can I export all messages at once?
Not at the moment. You can open any message and save it as PDF, EML, HTML or text, and save its attachments.
Is there a size limit?
There is no limit on the file size: the archive is read in pieces. In our test a 2.2 GB archive with 215,000 messages was listed in about 16 seconds and used under 200 MB of browser memory. One message opens up to 100 MB. Google Takeout gives you a .zip: unzip it and drop the .mbox file.