Mozilla Firefox, Portable Edition 4.0 Beta 1 Released By

John T. Haller's picture
Submitted by John T. Haller on July 6, 2010 - 8:07pm

Firefox is proud to announce the release of Mozilla Firefox®, Portable Edition 4.0 Beta 1. It's the latest beta of the upcoming 4.0 version of the Mozilla Firefox browser bundled with a launcher as a portable app, so you can take your browser, bookmarks, settings and extensions on the go. This release updates Firefox to the current beta version and has an improved launcher. The 4.0 Beta 2 Minefield Portable package has also been posted which automatically downloads and configures the latest nightly build of the upcoming Beta 2 release. It's packaged in Format so it can easily integrate with the Suite. And, as always, it's open source and completely free.

Read on for more details...

Mozilla®, Firefox® and the Firefox logo are registered trademarks of the Mozilla Foundation and are used under license.

English Only: Mozilla Firefox 4 Beta 1 was released as English only instead of the multilingual release expected. We have corrected the descriptions and download page to indicate that.


FirefoxPortable4_small.pngMozilla Firefox is a fast, full-featured web browser that's easy to use. It has lots of great features including popup-blocking, tabbed-browsing, integrated search, improved privacy features, automatic updating and more. Plus, thanks to the launcher bundled in the Mozilla Firefox, Portable Edition, it leaves no personal information behind on the machine you run it on, so you can take your favorite browser along with all your favorite bookmarks and extensions with you wherever you go. Learn more about Mozilla Firefox...

New In Firefox 4.0

  • Tabs are now on top by default on Windows only - OSX and Linux will be changing when the theme has been modified to support the change.
  • On Windows Vista and Windows 7 the menu bar has been replaced with the Firefox button.
  • You can search for and switch to already open tabs in the Smart Location Bar
  • New Addons Manager and extension management API (UI will be changed before final release)
  • Significant API improvements are available for JS-ctypes, a foreign function interface for extensions.
  • The stop and reload buttons have been merged into a single button on Windows, Mac and Linux.
  • The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you'd like).
  • Crash protection for Windows, Linux, and Mac when there is a crash in the Adobe Flash, Apple Quicktime or Microsoft Silverlight plugins.
  • CSS Transitions are partially supported.
  • Full WebGL support is included but disabled by default at this time.
  • Core Animation rendering model for plugins on Mac OS X. Plugins which also support this rendering model can now draw faster and more efficiently.
  • Native support for the HD HTML5 WebM video format.
  • An experimental Direct2D rendering backend is available on Windows, turned off by default.
  • Web developers can use Websockets for a low complexity, low latency, bidirectional communications API.
  • Web developers can update the URL field without reloading the page using HTML History APIs.
  • More responsive page rendering using lazy frame construction.
  • Link history lookup is done asynchronously to provide better responsiveness during pageload.
  • CSS :visited selectors have been changed to block websites from being able to check a user's browsing history.
  • New HTML5 parser.
  • Support for more HTML5 form controls. Installer / Format

Mozilla Firefox, Portable Edition is packaged in a Installer so it will automatically detect an existing installation when your drive is plugged in. And it's in Format, so it automatically works with the Suite including the Menu and Backup Utility.


Mozilla Firefox, Portable Edition is available for immediate download from the Mozilla Firefox, Portable Edition 4.0 Beta 1 homepage. Get it today!

Story Topic:


John T. Haller's picture

It's a nightly build (read: automated build, changes at least daily often more, untested and unsupported), so on any given day, it may or may not work on some or all OSes. If you want to test 4.0, stick to Beta 1.

Sometimes, the impossible can become possible, if you're awesome!

Unless you're talking about your portable launcher the nightly build works on the beta launcher just not the minefield launcher.

John T. Haller's picture

I just ran the installer and it installed the current nightly build and it fired up just fine on my Windows 7 x64 Ultimate box (Mozilla/5.0 (Windows; Windows NT 6.1; Win64; x64; en-US; rv:2.0b2pre) Gecko/20100706 Minefield/4.0b2pre). If you have a support issue specifically about the launcher, please create a new post in the support forum (not here as comments on a news story) and post the complete details of what does and does not work. The launchers are exactly the same except the splash screen, so something else is up with your specific setup.

Sometimes, the impossible can become possible, if you're awesome!

The minefield launcher using the 32-64bit version but for some reason it requires a 64bit OS.

PS. You're welcome to delete the comments since this is the wrong section.

John T. Haller's picture

It seems the installer was mistakenly download x64 Firefox instead of x86. I'm posting the fix now.

Sometimes, the impossible can become possible, if you're awesome!

I've been running Minefield since 3.7 started coming out with the dailies. Launched today on my Win 7 64-bit machine just fine.

The installer displays a certain weird behaviour.
It asks for Firefox to be closed before it will proceed installing.
That's not exactly wrong if it is to be installed in the same folder as the one currently in use. But since the beta will install itself in a different (test)folder there's no point in complaining about a currently active version.

John T. Haller's picture

This is by design. It asks anything running firefox.exe to close. This is because sometimes the launcher doesn't stick around. So a running firefox.exe could be any firefox, even its own.

Sometimes, the impossible can become possible, if you're awesome!

I don't see the point of that.
Whatever version of Firefox is running is not relevant as long as the installer installs whatever version in an empty folder.
Only when the installer detects that it is supposed to install something in a non-empty folder (containing firefox.exe) it should complain about that.

And BTW:
There are "real" problems: it seems that the localized Dutch version is just plain English. I didn't test the other localized ones but probably they're not translated too.

John T. Haller's picture

The installer checks for an already-running instance on startup. So it doesn't know where you're installing it yet. At some point, we may alter that, but it will have to take into account automated installs as well.

And you're right on the beta. All languages were English as Mozilla appears to have done 4.0 Beta 1 as English only but, oddly, set their download redirectors to download the English version if you ask for 4.0b1 in nl (or others). I've updated the pages to indicate this.

Sometimes, the impossible can become possible, if you're awesome!

Thanks for looking into my questions.

I've deinstalled the program anyway. I've > 50 addons and version 4 has serious issues. Most addons do not start, others error out and the interface is seriously malformed.
Mozilla still has to do some work here. Smile

I'll stick to the 3.6 series for now.

John T. Haller's picture

It's a first beta. So most add-ons won't work properly (unless they are incorrectly marked as compatible or have been updated in the last couple months specifically for 4.0). The beta period is to shake out bugs and to allow extension devs to update. It's not for everyday use.

Sometimes, the impossible can become possible, if you're awesome!

hey thx guys is realy great i find this i like thx Biggrin

I like a Portable software is simple but is very good i can't instal to my computer, but i can use is portable guys !