By Craig Buckler

What’s New in Firefox 10

By Craig Buckler

Firefox reached double-digit version numbers on January 31, 2012. It’s been a mere six weeks since we received Firefox 9.0 but there are several interesting features in the new version…

Page Inspector

Firefox now has it’s own built-in page inspector. To launch it, select Inspect from the Web Developer menu, point to an element and choose “Inspect” from the right-click context menu, or press Ctrl+Shift+I. The active element will be highlighted and a bar appears at the bottom of the window showing a clickable breadcrumb trail of the DOM hierarchy.

The HTML button shows the element’s location in the page source while Style displays an editable list of applied CSS rules and properties.

Firefox Inspector

Let’s be honest: it’s not Firebug. But it looks good, works well and will be invaluable on those rare occasions when Firebug isn’t available. I was a little concerned the Inspector would clash with Firebug in some way but I’m yet to encounter a problem.

CSS 3D Transforms

Like the webkit browsers, Firefox 10 now supports CSS 3D transforms which allow you to rotate, skew and translate objects in three-dimensional space. You’ll require the -moz prefix but I suspect more developers will experiment with the effects now they’re supported in Firefox, Chrome, Safari and IE10.

Fullscreen API

The fullscreen API is another webkit feature which has been implemented in Firefox 10. You guessed correctly — it allows a page to launch the browser in full-screen mode which makes it ideal for videos, games and other interactive media.

Before hackers and pop-up advertisers become too excited, you should note that the browser places several restrictions on the feature and users cannot be placed in fullscreen mode without their knowledge or consent. The API is not particularly stable; the W3C Fullscreen specification is an early draft and there are minor differences between the webkit and gecko implementations.

Visibility API

The visibility API allows you to check three new document true/false properties:

  • visible — your document is the foreground tab of a non-minimized window
  • hidden — your document is either a background tab or on a minimized window
  • prerender — your document is being pre-rendered and is not visible to the user

It’s simple but allow us to make more efficient and usable web pages. For example, changing tabs could automatically pause a video or slow down Ajax requests.

Dynamic Forward Button

The Forward navigation button now automatically hides itself when there’s no page to forward to! I’ve not heard anyone complain about wasted toolbar space, but it’s a logical interface enhancement since the button’s rarely used.

Firefox hidden forward button

Better Add-On Compatibility

Probably. Until version 10, Firefox assumed add-ons were incompatible if they were marked as valid for an earlier version. This was rarely the case and you could often force an add-on to install by changing the supported browser number. Mozilla has now reversed the policy; any extension which is compatible with Firefox 4.0 and doesn’t contain compiled code is presumed to be compatible.

Add-on issues have not been stopped completely, but the situation has improved considerably since last year.

Overall, Firefox 10 is a solid release with a good number of features. Say goodbye to version 9.0 and upgrade today … because version 11 will be with us on March 13, 2012.

  • Cool. Downloading my copy of the latest Firefox 10. Hope it will help us developers more than before.

  • Looks like I have to update my browser today… Some of the changes seem to be interesting

  • David Yarbrough

    I’d like to discuss the policy of quick releases of new Firefox versions and the Defense Industry. It appears to me that the quick version release approach (just six (6) weeks) is incompatible with the DoD’s and their vendor’s time consuming and expensive product vetting process. Given the extreme nature of the penetration attempts we face, it would appear that some sort of common vetting processes would be less expensive and less time consuming. It might also mean that Firefox would be more readily accepted s a Web browser in his environment.

    • I don’t think it’s just the Defense Industry. Few large organizations are willing to push out an untested browser when their whole web application infrastructure depends on it.

      Mozilla now have a Extended Support Release (ESR) program. In essence, a new version is only released every 30 weeks. It’ll start with v10 and the next update you’ll receive is v17. See:

      However, I suspect this is still too rapid for many large clients.

  • … and yet I’m still keeping 3.52 installed because it’s the last time the web developer toolbar worked right… or at least the parts I use of it.

    • Really? I thought it was all working fine – which features are failing?

    • Kise S.

      im using FF10 and the web developer toolbar works fine with no problems, i just had to reset the toolbar settings i think on version 5 and after that it worked to version 10

    • Ayoub

      Not even a week ago i was working with WDT in firefox 9. I expect it ll work just fine in FF 10

  • Modern Codes

    Very nice update. I like it.

  • Aaron Osteraas

    First Firefox update I’ve been impressed with for some time.

  • Great article Craig,

    These changes are very interesting, a big improvement overall, considering how fast these versions are coming from mozilla now.

  • Terence

    I know chrome has this feature, now firefox has this feature too. Good work. Also tried it in the firefox engine of Avant browser. The content menu works, but the shortcut crtl+shift+I doesn’t work, what a pity.

    • Uthael

      Works for me ;)

  • “I’ve not heard anyone complain about wasted toolbar space, but it’s a logical interface enhancement since the button’s rarely used.”

    I don’t know about this, I hate it when things menu’s change depending on the context.

    In Eclipse IDE if you have a bunch of files open and some of them are different file types, you cannot menu left arrow click back through recently used files, or rather you can until you hit a different file type then suddenly the menu changes slightly and you find you’re clicking on a different button. I really hate that.

    IMO menus should stay the same unless there’s a really bloody good reason not to. Frankly the amount of screenspace the Forward button takes up in a browser is inconsequential compared to the inconvenience caused by buttons moving around.

    • There’s a lot to be said for keeping things consistent, but that has to be weighed up against progress. I doubt many people will notice that the forward button disappears – after all, it’s only of use once you’ve hit back at least once.

      If you really don’t like it, someone’s almost certain to release an add-on which brings it back.

  • Eddie Sheehy

    It sucks. Yesterday my Version 9 ‘adopted’ the Version 10 features without warning. On top of that the initial page is now blank, even though the Options show that my home page should be loaded at start. Once I navigate to a new page the BACK button is inoperative and the Menu buttons on top are inoperative. I uninstalled Version 9 and downloaded and installed Version 10. Exactly the same problems. I have also uninstalled Version 10. I’m done

    • Anonymous

      Just type in your address bar “about:config” and accept the warning. After that enter “app.update” in the displayed search line and flip two values from true to false.
      If I remember correctly it is the first and one in the middle. They are about auto-updating you browser. I also do not like if FF does it automatically and learned that his will stop his behavior. You can check that new found empowerement in the about box where now a button is displayed and no upgrade occurs until you click (and therefore authorize) it.

      Hope that helps. Enjoy.

  • Well,

    Now that they have made it to the “gang of four” browsers, I guess it’s time to get off my rump and start grokking CSS 3D Transforms. Happy, Happy, Joy, Joy!


  • Marcelo

    Good article, firefox 10 have a lot of improvements and consume less memory, great!

  • T. Wrecks

    I had disappearing forward and back buttons in FF3. It’s called adding a couple of lines to your userchrome.css, dummy. Firefox was pretty good until somebody figured they could work straight through to retirement with a non-stop bombardment of endless new “features”. God Almighty, it’s like Microsoftosis has infected most of the so-called brains in the world.


  • First thing I noticed was that 10.0 no longer tells me which tab group is open. The top of the page and the taskbar window used to display the current tab group (that I had named), but now they just give the title of the page of the current tab. This is no help because the tab already gives me this info. My system for naming tab groups is now useless too. Other than that FF seems to be more stable.

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