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10 Things You Need To Know About Firefox 4


What is it?

Firefox 4 is Mozilla's fifth major browser release (including v3.6) that is designed to help Mozilla catch up with an increasingly fast development pace in the browser segment. While it is designed to compete with the current generation of rival browsers, especially IE9 and Chrome 10, it is Mozilla's last browser in an extended development cycle. The browser was first announced to be in development in May of last year, while the actual development of core features for the browser, including GPU acceleration support, has lasted more than a year and began with version 3.7. Mozilla released 12 beta versions between July 2010 and February 2011 and two release candidates earlier this month. Future Firefox versions will be released every 16 months (as final versions). Like Google, Mozilla will have at least three different browser versions in development at any given time. Firefox 5 is due to be released in the week of June 29 of this year.

2. What is new?

If you are transitioning from Firefox 3.6, you will immediately notice the reduced user interface, which now hides behind an orange Firefox button. The menu structure has been cleaned up as well. Under the hood, the browser now supports hardware (GPU, multi-core CPU) acceleration, sports the much faster JaegerMonkey JavaScript engine (which is still based on the old SpiderMonkey ), as well as a graphical interface for the organization of tabs, Panorama. Other new features include a new add-on manager, pinned tabs, syncing of the browsing history and bookmarks with other devices, including Android smartphones (via Firefox 4 Mobile), greater HTML5 support with Form features and a new HTML5 parser, WebGL and SVG compatibility, support for Google's WebM video format, multi-touch support for Windows 7, integration of Open Type Fonts, and Mozilla's version of a do-not-track feature. Firefox also separates its tabs and processes, which means that a crashed plug-in only affects a new and not the entire browser. 

3. So, how fast is it?

Benchmarks that were released over the past few months suggest that Firefox 4 has made improvements especially in JavaScript and GPU acceleration performance. We will be updating the detailed performance with an updated version of our Browser Grand Prix soon. However, it is common sense to assume that this version is much more competitive than the 3.6.x generation.

4. How does the hardware acceleration support differ from IE9?

There is an ongoing argument between Mozilla and Microsoft who really offers the most complete hardware acceleration. While Microsoft claims that Firefox and Chrome do not accelerate all levels that are accessible in Windows 7, Mozilla claims that Microsoft does not address the entire HTML5 platform and especially not all operating systems - as IE9 only supports Windows 7 as well as Windows Vista SP2.

Firefox accelerates content in the following way (source: Mozilla Hacks):  

The argument may soon change, however, as Google is preparing acceleration support also for plug-ins and Opera is promising full hardware acceleration for Windows XP in Opera 11.50.

5. Who should download Firefox 4?

It is still a lean, but much more capable browser. However, you may want to wait you’re your upgrade, if you depend on plug-ins: Add-ons for Firefox 3.x are not compatible with Firefox 4. If you don't use plug-ins, it’s a no-brainer to step up from version 3.x to 4.0. Keep in mind that there will be an update to version 4.1 or 4.0.1 within two or three weeks that will fix a few minor issues in the code.

6. Firefox 4, Chrome 10, or IE9?

Most users will have to answer this question for themselves. All three are very capable browsers that will run any current and near-future content very well. There are differences in HTML5 support and it is more than likely that each browser will display complex HTML5 in a slightly different way. That, however, does not matter in everyday browsing yet. Right now, my personal experience suggests that all three are very close in terms of JavaScript performance (differences are seen in very specific benchmarks - IE9 wins, for example Sunspider, but is way behind in Mozilla's Kraken, which is dominated by Firefox 4 and Chrome 10), all three offer excellent hardware acceleration, and all three offer modern user interfaces. Your operating system (Windows XP or not) and personal taste are most likely decide the use of the use of a certain browser. If you are running Windows Vista and Windows 7 and you do value slight feature advantages of browsers, then my recommendation is to install all three and test them on your favorite sites. Of course, there is also Opera, which is still a fast browser, but lacks hardware acceleration at this time. I suggest you wait for version 11.50 to give Opera a spin.         

7. Where do I download Firefox 4?

Windows :,0301-7374.html
Mac :,0301-7374-27688.html
Linux :,0301-7374-27690.html
Linux x64 :,0301-7374-27692.html

8. What about the update?

Mozilla will update your Firefox to version 4.0 through its usual update process. You can also simply download Firefox 4.0 and existing 3.x versions will be updated to the new 4.0.  

9.  Where can I find the menu bar?

If you are upgrading from Firefox 3.x, it is most likely that you may miss the menu bar. It has been removed by default to give web content more room. However, if you want to enable the menu bar again, you can find it by clicking the orange Firefox button (top left corner), and selecting Menu Bar from the Options menu.  keep in mind that panorama is one of the key features of the new Firefox interface, which can be access via a small arrow button on the right side of the top toolbar.

10. I am ready to go. Show me HTML5!

Accelerated, rich HTML5 content is what makes the new generation of browsers stand out. Especially Microsoft and Mozilla have been publishing lots of demos to showcase the new capabilities. You can find Microsoft's demo page here and Mozilla's demo page here. Mozilla has also launched a first version of its Open Web App Store platform with new applications that are worth trying

  • mosu
    I really liked this , it is consistent with my experience.
  • burnley14
    Have been using it for a while now, I definitely feel like it's much snappier than previous Firefox versions.
  • zoemayne
    Are ALL addons not compatible??? so there are no addons as of now? I can't upgrade if so.

    I'll compromise but I really need adblocker and some non-google bookmark synch
  • Can't find either the Stop or Refresh buttons and I don't really like the new "skin", and that Home cannot be colored to stand out. Other than that, okay but not too impressed.
  • Camikazi
    zoemayneAre ALL addons not compatible??? so there are no addons as of now? I can't upgrade if so.I'll compromise but I really need adblocker and some non-google bookmark synchI'm using adblock, noscript, ghostery and a few other add-ons with FF4 and have had not problems, been using FF4 since beta 6 and add-ons have worked (updates within a day usually).
  • Camikazi
    RosechCan't find either the Stop or Refresh buttons and I don't really like the new "skin", and that Home cannot be colored to stand out. Other than that, okay but not too impressed.On the address bar, right end next to the star is the Stop/Refresh button, one button for both if not loading it works as refresh if loading it works as stop.
  • I rate this post very low. I am unsure which audience is being targeted here. I am a simple user with basic needs like Video streaming, online games and you have absolutely no information here regarding them.

    With a title "10 Things You Need To Know About Firefox 4" you have no given any infact.

    E.g: 6. Firefox 4, Chrome 10, or IE9?
    Most users will have to answer this question for themselves.

    I believe the author had to make 10 points.

    I am very disappointed, even though I am an avid reader of your articles.
  • of the way
    Adblock Plus works for me.

    Seems fairly equivalent to Chrome in free screen space and speed for my general browsing.
  • @zoemayne - adblocker works, read it later doesn't
  • @zoemayne

    adblock plus and no script works with minefield 4.0b13pre so you should have no probs with them