Mozilla Firefox, Portable Edition 4.0 (web browser) Released by

John T. Haller's picture
Submitted by John T. Haller on March 22, 2011 - 1:45pm

Firefox is proud to announce the release of Mozilla Firefox®, Portable Edition 4.0 in 17 languages. It's the latest 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 new 4.0 release. All users are encouraged to upgrade. It's available in Chinese (Simplified and Traditional), Dutch, English, English (Great Britain), French, German, Hungarian, Italian, Japanese, Korean, Polish, Portuguese (Portugal and Brazil), Russian and Spanish (Spain and International).

If it's your first visit to in a while, be sure and check out our new apps including 100 new apps in 100 days (with another new app every day) and the current beta platform release with a built-in updater. Mozilla Firefox, Portable Edition is 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... Platform 2.0 Beta 5 users who already have this app installed, simply click 'Check for Updates' in your PA.c Menu to update to the new version.

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


FirefoxPortable_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... 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 homepage. You can get the German release from the German homepage and the other localized releases from the Localization page. Get it today!

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seems to be broken though

7 out of 10 of my add-ons (all compatible with 4.0!) don't work with it properly

all seems to be fine after installation, but after i tried to use it at another pc
they are gone for good - not even working any more from same pc and path

quite annoying as they were working fine with portable 3.x and it took me three hours to move all my settings add ons and passwords to 4.0 which is not working for me at all

Wow, three hours sounds like a lot of work.

I too wanted to retain my old (3.6) installation intact (just in case), so I copied the entire FirefoxPortable directory to a different name. I then installed 4.0 (updating) over one 3.6 copy, and it progressed very quickly.

I ended up with my old version intact and also the version that got upgraded to 4.0. No problems, everything works just fine.

You might get better results giving that a shot instead of trying to do it manually.

neutron1132 (at) usa (dot) com

NathanJ79's picture

...since those are in the FirefoxPortableTest folder. Rename the folder to FirefoxPortable and the updater will work.


(I actually quit using Portable Firefox at home, and it's amazing how the 4.0 betas (and now final) handle minor updates, it's much easier and more seamless than it was the last time I had Firefox installed. Still using Portable Firefox on-the-go on my portable hard drive (and all my other portable apps at home) though!

I'm upgrading to Firefox 4 by selecting "Help->Check Updates" from Firefox 3.x menu. Please just ignore my question below.
It's great to hear the portable Firefox 4 has been released. How to upgrade from Firefox 3.x so that I don't have to have all addon's, site passwords and histories lost?

All apps here support "in placer updates". That means your data is safe on updates as it resides in a folder which isnt touched by the installer.

"What about Love?" - "Overrated. Biochemically no different than eating large quantities of chocolate." - Al Pacino in The Devils Advocate

if you update from within just ff update as opposed to getting a new paf from here or useing the autoupdater in the menu, it's become unoptimized, since you didn't have the latest firefoxportable?

Don't be an uberPr∅. They are stinky.

Thanks John!

Too many lonely hearts in the real world
Too many bridges you can burn
Too many tables you can't turn
Don't wanna live my life in the real world

the icon for the "Like Firefox Portable, you'll love Firefox on your PC" needs a new icon for the 4.

Don't be an uberPr∅. They are stinky.

Thank you again John. Ummmmmmm 3.5.18 and 3.6.16 are out as well. Could we have at least the English version if it's not too much work for you?

John T. Haller's picture

We're building the legacy builds now (see here) and they should be out today. As with all legacy releases, they will, by default, install to a different directory (as they have a different AppID: FirefoxPortableLegacy35 and FirefoxPortableLegacy36 respectively) but you can manually select the old one and it'll upgrade an existing FirefoxPortable 3.6.x install.

No one should be using 3.5.x for anything but testing sites now. And 3.6.x will be maintained with security and stability improvements "for a short amount of time" (no more 6 month grace period, it seems) as Mozilla says "all users are strongly encouraged to upgrade to Firefox 4".

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

Thank you so much, John & team. I'm staying with 3.5 and 3.6 for now. Only used PortableApps' 4.0 just to explore it. Still not my primary version at the moment.

I am amazed and gratified at the speed of FF 4 portable. I thought I'd have to wait for USB3 to come on line before I could start using the portable version at work, but this update has resolved that problem!

It keeps crashing on my Notebook with Windows 7 Ultimate x64. But it's working well with Windows XP Professional x86 that I use on my work.

John T. Haller's picture

That's nearly always video drivers. Both FF4 and IE9 use hardware acceleration for everything in the browser on Vista/7 now (and Chrome uses it for some stuff). First, try updating your video drivers. Barring that (as some notebook manufacturers release very buggy drivers and never bother updating them), disable hardware acceleration by clicking Firefox - Options - Advanced - General and uncheck Use hardware acceleration. Once you close and restart, it won't anymore.

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

My notebook has a GeForce 9300M GS and I'm using the last driver I found on Strangely, the Firefox only crashes when it's its first start. I've installed it using the XP machine and now it's working aswell on my notebook! :]

FF3.x kept freezing momentarily on my W7 AMD 64 machine - but FF4 has been smooth as silk.

I made this half-pony, half-monkey monster to please you.

I install the portable FF4 in my office PC, the dir is H:\tools\portablefirefox4.
when i copy the portablefirefox4 dir. to my home pc at
C:\portablefirefox4, FF4 can start, but when i open the Tools->Add-ons->Extensions page, i can't see the addons which i install.
And i found some of the Addon can't work, FF4 works so strange....
Can someone help me?

Try copying it to C:\tools\portablefirefox4 instead.

Previously known as kAlug.

I have try copy to C:\tools\portablefirefox4 but it's still same problem.
Thank you for helping, but it's still can't work.

I try to upgrade my portableFF3.6.15 to portableFF4, it's work fine.
But when i just install protableFF4(not upgrade from old version, just new install),
it's can work.
This situation is so strange....
But now it's final work by use upgrade way.
For everybody reference.

Hi, I already have Firefox Portable 3.6 and would like to keep it for comparison when I install v4, if I change the 3.6 folder name from "FirefoxPortable" to something else will it leave the old version alone?

Thanks for any help.

When I start this it says; "Thanks for downloading Firefox 4 RC."
Shouldn’t this be the final release?