By Craig Buckler

Firefox 4.0 Released Today

By Craig Buckler

Following a year of development and several schedule slippages, Mozilla will release the final version of Firefox 4.0 later today at If you can’t wait, I’m going to let you in on a little secret … Firefox 4.0 is already available to download from Mozilla’s FTP servers. Don’t tell anyone else!

We’ve been using Firefox 3.x for a long time. Version 3.0 was released in June 2008, 3.5 arrived a year later, and 3.6 came out in January 2010. The browser has begun to look a little dated following rise of Chrome, Opera’s new interface, and IE9’s release last week. Firefox may remain the top browser for development, but its speed has been criticized and many users have switched to Chrome.

Firefox 4.0 could redress the situation. It includes:

  • A new, streamlined user interface.
  • Enhanced performance courtesy of the new JägerMonkey JavaScript engine and graphics hardware acceleration.
  • Application tabs and tab grouping.
  • Built-in bookmark, open tabs, history, preferences and password synchronization.
  • Improved privacy controls and security.
  • Improved HTML5 capabilities such as new form elements, high-definition hardware-accelerated WebM video and 3D WebGL.
  • CSS3 transitions and transformations.
  • A revamped add-ons manager.
  • Multi-touch for some touchscreen devices.
  • A new web console.
  • Crash protection.

What’s more, it’s available in more than 70 languages and can be installed on most operating systems. Including Windows XP.

Obviously, another browser means more effort for web developers. However, you can install v3.6 and v4.0 side-by-side, you’re unlikely to experience radical rendering differences and, with luck, Mozilla will push Firefox 4.0 out as an automated update within a few weeks.

Will you install Firefox 4.0? Will it help the browser increase its market share? Or is it too little, too late? Watch out for a full review on SitePoint soon…

  • pothi

    Can’t wait for Firefox 4. I tested RC for a few days. Unfortunately that (RC) was not compatible with firebug and a few other plugins. Hope everything is okay now!

    • Louis Simoneau

      I’m running Firebug and all my usual extensions in the current RC.

      • Jon Randy

        Same here

    • fvsch

      Firebug 1.7 final, compatible with Firefox 4, was released yesterday.
      Previously, you could use the betas (or even alphas) of Firebug 1.7. I switched to Firefox 4b7 and Firebug 1.7a5 or something like that back in October or November. ;)

    • Tilak

      Same with me, I am also unable to use FireBug and other plugins.

  • Stormrider

    Been using the release candidates. It’s good, but occasionally crashes my video driver… just means the screen goes black for a couple of seconds then everything is back to normal. Firefox itself doesn’t crash, just a bit annoying when it does it.

  • Stormrider

    All my extensions work by the way (had to find a couple of them manually to install the latest version) apart from 1 – Screengrab! – but that looks like it hasn’t been worked on in years anyway, and there are alternatives. It’s a shame Colorzilla doesn’t have a button you can put on the toolbar as well, as it forces me to display the addon bar at the bottom of the screen just to be able to use it (without the keyboard shortcut).

    • fcphdJim

      The ColorZilla menu shows in the right-click contextual menu. Also, in the Firefox drop-down menu, it is in the Web Developer sub-menu. No need for any buttons or icons. I like it!

      • I have ColorZilla on my status bar – only it’s gone from bottom left to bottom right, next to Firebug.

  • Jon Randy

    Not sure if that will be the final build. Build 3 of RC2 is dated later than that build

  • ChrisH

    Well, been using FF4 RCs for a week or so, but ditched FF entirely today when I discovered it chewing over 8GB of my 12GB RAM. Goodbye Firefox, hello (again) Chrome (hopefully they’ve improved its JS handling).

  • Per Allan

    Yes, just go to the Firebug website and download v1.7.x.
    Works like a charm :)

  • frann

    It’ll have to speed up a lot for me to go back to it. I just keep it around for FireFTP

  • Scott

    Firebug 1.7 does indeed work with the RC on OS X.

  • Jon Clayton

    I have been doing some beta testing for the 4.0. I am pleased with it.

  • Mircea Chirea

    I doubt I’ll be switching from Chrome even 5 years from now. Google’s integration with the rest of their services is spectacular, especially the synchronization – you can sync everything from bookmarks to extensions to other installations on different operating systems.

    That and with the process/tab operation giving excellent reliability (especially from Flash, which LOVES to crash on 64-bit Linux), there’s 2 massive deal breakers for switching back to Firefox.

  • Mo

    I do hope Firebug will work, I can’t manage without it!

  • Chris

    FTP link doesn’t work, heres the correct path:

  • BIlal

    Just installed 4.0 and its amazing with features

  • Russ Weakley

    It’s now officially live:

  • Neil H

    “you can install v3.6 and v4.0 side-by-side”

    Please could you explain how, I have tried a couple of times, but the install forces an update without option of seperate install?

  • CG

    It just crashed my pc freezing all my open applications :(
    Norton adds on gone too.

  • Andrew

    At this point, I will install Firefox for testing purposes only.

    I can’t imagine switching back to it even as a development tool. It’s just too slow!

  • Prof. John C. Fish

    Ooops, I told EVERYONE xD

  • Daquan Wright

    Sweet! Firefox 4 feels a whole lot more snappier and the flash playback has been improved as well. Firefox 3.XX just started feeling all slow and bloated. It’s going to need to get simpler and quicker if it doesn’t want chrome taking its share.

  • IE9 was downloaded 2.3 million times in the first 24 hours.

    Firefox fans will be pleased to hear that downloads have just exceeded 2.4 million within 6 hours. I guess a large proportion are XP users…?

  • kaf

    First impression:

    It’s FAST!

    Not used to saying that about firefox!

  • Dan

    First impression: really slow.

    FF4 takes 21 seconds to start, whereas Chrome takes 4 seconds. I’ll stick with Chrome.

    • kaf

      I doubt anyone is measuring speed based on startup time. It’s more page load time. How often do you restart your browser anyway? Besides it takes about 5 secs for me so it’s probably just cos it’s the first time.

      We all have to use FF anyway because firebug for ff is the only debugging tool that is actually usable. So we may as well rejoice for anything that makes our jobs easier.

      btw I’m sticking with chrome too for personal use.

  • Party Bus DC

    Firefox 4 Features

    Get to your favorite sites quickly – even if you don’t remember the URLs. Type your term into the location bar (aka the Awesome Bar) and the autocomplete function will include possible matches from your browsing history, bookmarked sites and open tabs.

    The Awesome Bar learns as you use it—over time, it adapts to your preferences and offers better-fitting matches. We’ve tweaked it to give you greater control over the results (including privacy settings) and increased performance so you find what you need even faster.

  • wanderer

    where would we be now wothout Firefox?

  • mahen23

    Mozilla really fails at developing a better user experience for its browser. They are still using the same download manager from FF1.0 and they stole their new menu from Opera Software.

    Compared to IE9, they really do give a really better user experience to the user. The new download manager, autocomplete popups that are less noisy. Mozilla fail this time.

    • Is the download manager really so bad? What improvements would you add?

      The menu has certainly been influenced by Opera but I think they’ve made a better job of it. In Opera, I have the old menu enabled because it has all the options and I find it quicker/easier. The Fx4 menu is organized better and I don’t need the full menu.

  • hground

    Loaded FF 4 on my work machine (XP – SP3) and it started crashing ( BSOD – apparently my machine’s video card. Updated drivers, but still had a crash). Went back to 3.6 – hope the problem is gone for good now. Will have to wait awhile to try it again – too much lost work time!

  • Patrick Samphire

    Just downloaded FF 4 and it seems good, although I’m seeing a couple of bugs on one of my sites related to transitions and hover. Have to look into what exactly is going on. Don’t have the same bugs in Chrome.

    Overall, if it crashes less than Chrome when streaming Flash video, I’ll probably switch back. If not, I’ll probably use both as I tend to now.

  • Gabe

    If Firefox used V8, I’d consider making the switch back. This way, there’s no chance I’m letting Chrome go.

  • Jay

    Firefox 4 does not open saved searches that Ebay sends through email.
    Firefox 4 does not open the menu buttons for the my.msn home page. All my watched stocks are missing
    Firefox 4 is slower than the previous version.
    Have to switch to Explorer to follow my stocks. What a disaster!!!!!!!!!!!!!!!!1

    • Gary

      “Firefox 4 is slower than the previous version”

      Did you get that out a christmas cracker.
      Nobody who has used the new Firefox 4 will think the same.

      It is blindingly fast, and it whacks Internet Explorer (as usual) on standards support.
      Woohoo IE just got SVG, Firefox had it years ago.

      Still no MathML in the IE browser so users are forced to hunt around for plugins to do the job. This despite the standard being implemented in firefox in 3.0

  • Dacha

    I have strange problem with FF4 (Win XP) – on start, before I load some page, firefox.exe process use 50% of CPU!

  • Jay

    This morning all of my Ebay complaints have been resolved. Knock on wood.
    Now to fix the my.msn home page non-working menu buttons and my watched stock list to reappear.
    Things appear to run a bit faster also.

    • Todd

      I am having same issue with FF4 and my.msn – no stocks showing! Did anybody find a fix for this yet?

  • Patrick Samphire

    I’m back on Chrome. Feels just a few too many bugs on FF4. I suspect they released too quickly because of IE9. Hope they patch soon.

  • Silvester Yoo

    FF4 rocks! i tested in winXP machine but minefield 4.2 is better
    Javascript benchmark:
    Minefield:423.0 ms
    FF4: 469 ms

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