Free Online MBOX Viewer
Open, view, and search MBOX mailbox archives privately in your browser. Perfect for Google Takeout Gmail backups. Processed locally in your browser with no size limits.
Drop your MBOX file here
or click to select from your device
See an example before choosing your own file.
How to open a MBOX Archive file online
No registration and no installation required. FileViewerHub processes supported MBOX Archive files locally in your browser.
Drop your file
Drag and drop your .mbox file (like a Google Takeout export) into the secure browser sandbox.
See it instantly
Our client-side parser reads and formats the MBOX mailbox database directly on your device in milliseconds. No data is sent to external servers.
Export or move on
Browse the message index, search emails, view HTML formatting, and download attachments before closing the tab.
What Is an MBOX File?
An MBOX file is a mailbox archive format used to store multiple email messages in a single file. It is commonly used by email clients and export tools such as Google Takeout, Mozilla Thunderbird, Apple Mail, and other mailbox backup systems.
MBOX files are useful when you need to archive, move, inspect, or search large collections of email messages outside your regular inbox.
To open an MBOX file with FileViewerHub, select your .mbox file from your device or drag it into the viewer. The file is processed locally in your browser, and the mailbox is indexed so you can browse individual messages.
Powerful Client-Side MBOX Tools
FileViewerHub processes your email archive files inside your browser for instant viewing, search querying, and attachment downloading without compromising your privacy.
Fast Local Mailbox Indexing
MBOX files can package thousands of emails into a single heavy text file. Our client-side indexer parses the database structure directly on your device, creating a clean, scrollable message list. You can navigate between email folders, browse sender indexes, and preview contents in milliseconds without importing into an email client.
Advanced Sender & Subject Search
Searching through a massive Gmail backup is effortless with our built-in search. Filter messages instantly by sender, recipient, subject line, or date range. The search runs entirely in your browser's local memory, delivering lightning-fast results without sending queries to a server.
Extract Attachments Privately
Identify and download document, image, and PDF attachments from any email in the MBOX archive. Our parser decodes the attachments locally within your browser sandbox, keeping your private files, spreadsheets, and photos secure on your machine.
What You Can View inside an MBOX Archive
Open Google Takeout MBOX Files
Google Takeout exports Gmail messages as MBOX files. FileViewerHub helps you inspect these exported mailbox archives without importing them into another email client. After downloading your Google Takeout archive, extract the .mbox file and open it in the MBOX Viewer to browse your saved Gmail messages.
Open Thunderbird and Apple Mail MBOX Archives
Mozilla Thunderbird and Apple Mail also use MBOX-style mailbox files for storing email folders and archives. FileViewerHub can help you open supported MBOX archives directly in the browser, making it easier to inspect email backups without installing or configuring a mail client.
What programs open MBOX files?
Mailbox archives are standard and supported by several email client utilities.
MBOX vs EML: What Is the Difference?
An MBOX file usually contains many email messages inside one mailbox archive. An EML file usually stores one individual email message.
If you have a full mailbox export, use the MBOX Viewer. If you have a single saved email message, use the EML Viewer.
Is It Safe to Open MBOX Files Online?
MBOX files can contain years of private emails, attachments, business records, and personal information. FileViewerHub is designed to reduce privacy risk by processing supported MBOX files locally in your browser. Your MBOX file is not uploaded to FileViewerHub servers for standard viewing. The mailbox is read on your own device, and the email content remains inside your browser during processing.
MBOX files can contain large personal email history. Keep files secure on your device and only view trusted archives.
Tips for Large MBOX Archives
Large MBOX files may take longer to open because they can contain thousands of email messages. For better performance, use a modern desktop browser, close unnecessary tabs, and work with smaller mailbox exports where possible.
View a sample MBOX Archive file
sample-mailbox.mbox
Not sure what you'll see? Open our safe sample MBOX file as an example to preview how the viewer indexes, splits, and displays messages and attachments.
Frequently asked questions
What is an MBOX file and where does it come from?
Can I open MBOX files without Thunderbird or Outlook?
How can I view a Google Takeout Gmail backup file?
Does this online MBOX viewer have mailbox file size limits?
How can I search for specific emails inside a large MBOX file?
Is my private email archive uploaded to any web servers?
Can I extract individual email messages and download attachments?
Ready to view your file?
Select your MBOX file above to browse mailbox messages privately in your browser.