Mozilla Firefox, Portable Edition 5.0 (web browser) Released

John T. Haller's picture
Submitted by John T. Haller on June 21, 2011 - 11:28pm

Firefox is proud to announce the release of Mozilla Firefox®, Portable Edition 5.0 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 5.0 release and improves extension portability. It's open source and completely free.

Update automatically in the Platform 2.0 Beta 5 by clicking 'Check for Updates'.

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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John T. Haller's picture

It should be noted that with the new 5.0 release and Mozilla's new rapid release cycle, the 4.0 release is not being treated as a legacy release as 3.6.x was. Users are being automatically updated to 5.0 (no "Do you want to upgrade to 4.0?" as with 3.6.x) and I don't think the 4.0 branch will be maintained now that 5.0 is out. This is much as Chrome updates are handled.

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

John T. Haller's picture

Firefox 4 should no longer be used for production use. Firefox 5 is the security and functionality update for Firefox 4. You can fake the version number to a specific website using an extension for websites that have no idea what they are doing (like your bank), there are a few available.

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

John T. Haller's picture

It's building now and will be out today. I highly recommend switching to 4.0 (now 5.0), though as 3.6.x will only be maintained for 'a short time', not the 6 months that Mozilla used to do for legacy releases. Upgrading is easy, you just install the new release over the old. If you're concerned about issues, just back up the whole directory first.

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

It's the loss of extension functionality that keeps me keeping at least
one machine with 3.6.x on it.

Extensions have always made FF attractive, yet many get left behind.

same here, they're upgrading too fast for the addon authors to keep up. Firefox needs to slow down and fast. I refuse to upgrade until my addons work properly

John T. Haller's picture

Extensions just need to be updated to show compatibility going forward. Extension developers have had well over a year to prepare for Firefox 4. Any extension that was not updated for FF4 probably should not be used anymore.

Firefox 5 doesn't break anything in terms of actual code in extensions over FF4, just extensions that listed only compatibility through FF4. So, folks should grab the Compatibility Reporter Addon (extension) and enable their extensions under FF5, ensure they work, and report them as working. Once Mozilla gets enough reports, they just flip a switch at and it reports back to Firefox that, yes, the extension will work fine with FF5 even though it's only marked as compatible through FF4. The extension doesn't even need updating by the developer or the user. Firefox handles re-enabling it.

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

Compatibility Reporter didn't work for my addons. I was lucky to find the developer version on my most critical addon. I recommend turning off any automatic update in Firefox and sit on your current version as long as possible. Updating is simply too risky. These kinds of problems don't happen with Chrome or Opera. with this frequency.

John T. Haller's picture

It just depends on the extensions. Some extensions simply aren't maintained as well. There's no real way around that. When a developer has 12 months to update an extension for 4.0 and doesn't, I wouldn't rely on that extension anymore.

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

I used to do that too, but I just upgraded to FF5 and I use Nightly Tester Tools addon and set it to 'force compatability'.
Everything is working nicely.

It's happening the same as in the previous versions.
I had Firefox Portable in Spanish (Spain) [es-ES] locale, and when PA.c updater gets the new version, it downloads the Spanish (International) [es-AR] locale, which is wrong.
I have to manually download and install the right [es-ES] one.


John T. Haller's picture

The updater only looks at what language you currently have the platform in, not what language the app itself was in. Did you have the platform in SpanishInternational when you updated?

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

If I edit the 'compatibility.ini' file in the Data\profile directory from this:


to this:


my bank likes 5.0

{changed the 5 after the = sign to a 4}

The only problem, Firefox changes it back on start up. It's a work around until my bank updates its browser list.

Sorry, posted reply in the wrong place.