View your Gmail archive without Thunderbird

What you will learn

When you export your Gmail account through Google Takeout, you get your emails as one big file with the extension .mbox (or .mbox.gz if it is compressed). Most guides then tell you to install Thunderbird to open that file. But that means installing a whole email program just to take a quick look inside an archive.

This article shows a faster way. With Mbox Viewer by Cloud Captains, a free Chrome extension, you open your Gmail archive directly in your browser. You drag the file in and start reading right away. No email program to install, no account to create, and, importantly, nothing gets uploaded.

What a Gmail archive actually is

Google Takeout is Google's official export service. It lets you download a copy of your own data, including your entire Gmail. That mail arrives in the so-called mbox format: a text format that stores all your messages one after another in a single file. It is a standard used by many email programs.

Because it is such a large, raw file, you cannot simply double-click and read it. You need a program that can unpack and display it. That is exactly what Mbox Viewer does.

You will often receive the file compressed as .mbox.gz. That is a zipped-up version. Mbox Viewer unpacks this automatically, so you do not have to extract it yourself with another tool first.

Why this is handy

• You do not have to install and configure a full email program like Thunderbird.
• Your archive stays entirely on your own computer. Mbox Viewer works locally and offline.
• You can search straight away using powerful operators (for example by sender, date or attachment).
• You read in a familiar layout: list on the left, message on the right, just like Gmail or Thunderbird.
• You can export individual messages as PDF, .eml or .html if you want to keep or forward a few.

Step by step: opening your Gmail export

Finding your way in a large archive

A Gmail archive can hold thousands of messages, so searching matters. Above the list you type a query. Besides plain words, you can also use targeted operators:

You can combine operators, for example from:bank has:attachment after:2021-01-01. There is also a regex mode for advanced users, and you can save frequently used queries so you can reuse them later.

Organizing and retrieving messages

Besides searching, you can bring order to your archive. You can give a message a label (tag), a star as a favorite, or add a note (a Captain note) to write down why a message matters, for instance. You can also filter by attachment, by source file and by date range. All of this stays stored locally alongside your archive.

External images and privacy

Many old emails contain images that only load when you open the mail. Some of those are tracking pixels: tiny, invisible images that let a sender see that you opened a mail. That is why Mbox Viewer blocks external images by default while you read. If you do want to see the images in a specific message, you load them with a button, per message. That way you decide what gets loaded.

Keeping or forwarding a few messages

If you want to keep a handful of messages separately, you can export per message as PDF, .eml, .html or .mbox. If you have selected several messages, you can export them in bulk, for example as a ZIP with all the EML files, a ZIP with PDFs, or a CSV with the metadata (sender, subject, date). When creating a PDF you choose what goes in, such as the headers, the text and optionally an attachment list.

Taking your workspace with you

All the labels, stars and notes you add belong to your browser on this device. If you want to continue later on another device, you can export your workspace from Settings and import it again on the other device. And when you are done and want to clean everything up, choose Clear database in Settings. After that, nothing from your archive remains in the browser.