Introducing Aurora 11 with tons of new features and improvements

We have now released Aurora 11, soon to become Firefox 11, and wanted to cover all the the things we have improved in this version!


  • To quickly edit the outerHTML of an element, we have now added support for element.outerHTML.
  • The Battery API
  • Storing files in IndexedDB
  • Support for loop attributes for media elements
  • SPDY (off by preferences)
  • WebSockets no longer needs a prefix when you call them

All new features

Below is a list of all the new improvements in Aurora 11, grouped by category together with a link to each bug in bugzilla if you are interested in reading up more about it and its process.







About Robert Nyman [Editor emeritus]

Technical Evangelist & Editor of Mozilla Hacks. Gives talks & blogs about HTML5, JavaScript & the Open Web. Robert is a strong believer in HTML5 and the Open Web and has been working since 1999 with Front End development for the web - in Sweden and in New York City. He regularly also blogs at and loves to travel and meet people.

More articles by Robert Nyman [Editor emeritus]…


  1. Robson Sobral

    Sadly, this improvements doesn’t makes the common user happy. I’m loving the improvements, but the people I know who just want to navigate is saying that Firefox doesn’t change since version 4.

    December 23rd, 2011 at 12:55

    1. Robert Nyman

      Different releases have different focus, and I believe both performance and web technology support improvements will give them a better experience.

      With that said, I understand what you are saying, and look forward to more visual and user experience changes in upcoming versions of Firefox!

      December 23rd, 2011 at 13:21

    2. nyan

      Another perspective. Users are also afraid of visual changes. They can be confusing and destroy the work-flow. A lot of users are happy when things look as they did.

      December 25th, 2011 at 07:49

      1. Robson Sobral

        There are some improvements, some of them I already saw at BugZilla, that can make common users happy without change too much the interface. A new home tab and new download manager, click to play plugins, unload unused tabs to disk, import of Chrome profile data, a button to unclose a tab, etc.

        December 27th, 2011 at 08:53

      2. Robert Nyman

        Definitely. It’s a matter of doing the right changes. Sometimes small careful ones, but sometimes major ones can make so much sense most people will just like it.

        December 30th, 2011 at 17:21

  2. Robson Sobral

    Good to know! Thanks for clarify this!

    And I agree. Better performance is really good. The day Firefox gives back resources when I close a tab, I’m gonna make a toast!

    December 23rd, 2011 at 13:41

    1. Robert Nyman

      Sounds good! :-)

      December 30th, 2011 at 17:21

  3. Jonas Sicking

    You missed that IndexedDB now support all key types, including floating point numbers, dates and Arrays!

    All in all our indexedDB implementation is now basically feature complete. Though we are not exposing error information quite well enough yet.

    And expect more performance improvements, especially with regards to storing very large numbers of files.

    December 23rd, 2011 at 17:16

    1. Robert Nyman

      Actually, it’s mentioned in the DOM section of the blog post – not just amongst the highlights. :-)

      December 30th, 2011 at 17:22

  4. John A. Bilicki III

    While the updates are great they are overwhelmingly too frequent.

    – Rapid releases don’t benefit me as a web designer / web developer as I have to fight Firefox from automatically updating profiles as I have them set for different versions and reconstruct them for new versions. Channels don’t make sense as I test older versions. Too many huge version numbers are irrationally over-bloated with not enough changes to justify a release.

    – Rapid releases don’t benefit me as a a blogger. Honestly I’ve stopped caring about promoting Firefox. A new version? I had a lousy paragraph’s worth to “hype” up the release of which the few things that got in to that release was the proprietary Microsoft insertAdjacentHTML method (and it’s still non-standard as Microsoft’s methods don’t register with the DOM correctly at the application level). There are some exciting new features but they are spread so thin that it’s a CHANCE that a new version will have something exciting in it, so why bother with three worthless releases that pretty much only artificially beefed up the version number? Bigger version numbers mean nothing, I’ll pick Firefox 1.5 with CSS3 multi-column support over Netscape 4 any day.

    – Rapid releases don’t benefit me as a user. A new version? Great! Why the heck are my toolbars being messed with? Wait…why are you people copying Internet Explorer 9’s atrocious anti-intuitive layout?

    – Rapid releases don’t benefit me as a computer repair person. Clients, family and friends are all upset that Firefox’s toolbars are being messed with and constant updates that don’t do anything except for mess with everything that I cleaned up and fixed so they’re all sticking with older versions.

    – Rapid releases don’t benefit corporations that were FINALLY moving away from Internet Explorer and now Mozilla is being perceived as immature and irrational. A non-technical person has to ask a web-enthusiast why thousands of computers have to be updated two months later and he replies that they added support for a proprietary Microsoft method and a small miscellaneous CSS property? Yeah, that doesn’t sound like any justification for the money spent on the time wasted on every-other-month releases.

    – Rapid releases don’t benefit users. Those cutting edge features aren’t going to make it to mainstream non-technical users any faster. In fact this approach is more likely to damage earlier implementations of new technologies as they are overwhelmingly not yet matured and changes in those standards are likely making backwards compatibility absolutely unacceptable if you start trying to use multiple things considering the poor upgrade rate of users overall. Let’s also keep in mind extension authors and the artificial maxVersion element. I’ve LITERALLY set my extensions to a maxVersion of over nine thousand and not for the sake of humor.

    – Rapid releases don’t benefit Firefox. There is absolutely nothing beneficial about rapid releases in any context. Sure, there will be fanboys who think copying Google is important. I have some who visit my site wondering why it won’t detect the difference between a nightly and aurora build when there aren’t any DOM or Script changes committed making it possible to detect the difference as if I don’t know what I’m talking about.

    So if Mozilla wants to undo the damage stick to a six-month release at minimal. Mozilla has pretty much alienated everyone. That’s why the upgrade charts look the way they do here:

    December 23rd, 2011 at 23:08

    1. thinsoldier

      – I completely agree that the increase in version number is too big with each release.

      – It’s true that rapid releases don’t appear to benefit the average user but hopefully there are some vital security updates included in there.
      In the long run the new features will benefit you as a web designer and then you will use them to benefit your users.

      – I remember the Chrome people bragging about how a lot of corporate environments were moving over to chrome.
      It does take a lot of extra time, effort, and manpower to support corporate accounts. Mozilla probably doesn’t have the resources for it. Google probably does.

      Wait, doesn’t Chrome release more frequent updates than all the other browsers?

      Anyway in addition to “added support for a proprietary Microsoft method and a small miscellaneous CSS property” they are laying the groundwork for much more significant css properties, faster rendering, more security, less memory hogging, better JS/DOM aps, etc. The only thing you heard about was the css but have you actually looked at Bugzilla??????????

      “”Yeah, that doesn’t sound like any justification for the money spent on the time wasted on every-other-month releases.””
      But this work was going to be done ANYWAY. The only difference is now things that are READY TO GO can GO LIVE NOW instead of waiting on a few completely unrelated, big, difficult things to be finished first.

      – The issues with the extension is something that is being worked on and will be addressed by improvements in a (hopefully near-) future update. For example I think firefox no longer disables extensions by default when updating.

      – If/When mozilla moves firefox to Google Chrome-like (& IE 9/10 -like) SILENT UPDATES you’ll have less to complain about, provided they make it possible for you to easily disable the silent updates. And they make announcements about if an update will drastically change the UI again.

      Thankfully i’m on a mac where the firefox ui seems to never get changed ever.

      December 27th, 2011 at 10:59

    2. Robert Nyman

      John A. Bilicki III,

      Thanks for your input!

      – Rapid releases for web developers: I’d argue that with Rapid releases we can get features out there in a swift manner, whereas before it could be done for up to a year before it saw the light of day, just waiting for the next major release. I understand that it is not smooth with profiles, but I would say web developers definitely gain from it overall.

      – Rapid releases for bloggers: It depends from version to version how much there is in it, but for instance, I would say that the above list is pretty comprehensive for one release.

      – Rapid releases for users: we can constantly make user’s privacy, web browser performance and experienced rendering better. With toolbars and similar, it’s a delicate balance.

      – Rapid releases for computer repair person: see reply above about toolbars etc.

      – Rapid releases for corporations: we are working on that, and you can read more in the proposal for an Extended Support Release (ESR).

      – Rapid releases for users when it comes to extension compatibility: The plan is, starting with Firefox 10, third-party hosted add-ons, or add-ons installed by third-party software, will be treated as compatible by default.

      –Rapid releases for Firefox: I hope the given arguments above helps answering this. I believe upgrades rely on a number of factors, but if we talk about web browser upgrade rates and web browser share, I believe Google Chrome has the biggest momentum right now, and they also apply a rapid release approach.

      To add to that, silent updates is also part of the plan, to make things as smooth as possible.

      December 30th, 2011 at 17:41

    3. tommy kay

      Amen, brother. You said so many things I was thinking.

      Stop with the continual updates.

      February 11th, 2012 at 10:41

  5. pd

    Is it possible that, since files can be stored in IndexedDB, we might finally see some improvements to the very broken browser caching experience?

    As a web developer I’d love to be able to send some instruction in my code to store various long-term files in IndexedDB and only update them exactly when I say they should be updated. With the current caching scenario, it’s much less finite than that.

    December 24th, 2011 at 09:11

    1. Robert Nyman

      I hope that will be improved.

      December 30th, 2011 at 17:24

    2. abral

      Yes, you can do everything you want with the files in IndexedDB.

      January 30th, 2012 at 06:48

  6. Gio

    Why the input tag type:numeric with spinner + and – don’t work?

    December 25th, 2011 at 04:00

    1. Robert Nyman

      Not sure what you mean, but if you talk about <input type=”number”> it doesn’t have any interface elements connected to it.

      December 30th, 2011 at 17:25

      1. pd

        I expect Gio is referring to the textbox type=”number” as is similarly implemented in XUL:

        It really is depressing to see all that handy controls that XUL – and therefore every release of FIrefox – already has built in, but which are not exposed/usable by web developers.

        I’ll say it once, I’ll say it 1000 times: screw HTML5 if it doesn’t finally get the basics right such as elementary, zero-JavaScript form controls with default styling such as those already implemented in XUL and basic desktop GUI toolsets over a decade ago.

        December 31st, 2011 at 07:14

        1. pd

          December 31st, 2011 at 07:16

        2. Robert Nyman

          The XUL implementation and the HTML5 is not the same ones, so it’s not just something that you can take over.
          Implementing HTML5 controls and user interfaces is of course on the list, but it haven’t been implemented yet.

          January 2nd, 2012 at 04:47

          1. pd

            Not good enough. I really wish I was wrong in my analysis that Mozilla’s developer support, and therefore open web promotion, is somewhat misguided. Not only are developer support resources being spent on native tools at the cost of Firebug improvement – including the fixing bugs like the JSD staying active that force every Firebug-using developer to tolerate bloated Firefox performance – but fundamental form elements, the sort of web application building foundations that non-web developers have taken for granted for over a decade, are *not* being made native!

            Isn’t it time that Mozilla took a look at ways it could make the development of lo-fi everyday web application simpler? The high-level, future-gazing stuff has seemingly been done. WebGL for gamers; web fonts for graphic designers; Flash replacement (canvas, SVG) … priority is going everywhere but, whether deliberate or not,priorities are not necessarily improving the ease with which everyday simple web applications are built. This despite the goal to encourage web apps and the web on mobile phones instead of native apps.

            Flash replacement and other priorities (not all of which are mentioned above) of course are very worthwhile priorities but it really is a kick in the pants every time some evangelist like Heilman manages to pull his evangelical mind out of Smashing magazine neo-cult gatherings to criticise every developer who dares use table layout or semi-colons in JavaScript whilst ignoring Mozilla’s lack of fundamental support for minimal web application form elements.

            In an era when Google has added speed to it’s ranking algorithm, and every speed-improving tip suggests minimizing http requests, Mozilla still forces developers to do several extra http requests in order to load JavaScript libraries just to provide form elements that should be native. In the mobile sphere where high latency is a nightmare, this really doesn’t make much sense.

            Isn’t it time for less head-in-the-clouds, future-gazing thinking within Mozilla circles and more focus on bridging the gaps between HTML4 and HTML5 that everyday developers are still falling through?

            Of course the XUL controls are not trivially ported to HTML however surely the ‘trip’ is not as long as it would be if the XUL elements were not already built?

            Anyway I’ve probably gone way past the point where freedom of speech is curtailed by the desire to speak in a different forum (the newsgroups) :) Sorry.

            January 2nd, 2012 at 06:13

          2. Robert Nyman

            If we talk about HTML5 form elements and support, it’s not just black and white, though. Every implementation is different, in my opinion, not one is perfect and definitely has its cons, and there are very few ways to control the visual presentation of the elements. I’m grateful that Opera and Google Chrome have been implementing and trying things, and we have all learned from that, but I believe it’s a long way to go for everyone.

            This is what we have accomplished with Firefox in 2011:

            When it comes to priorities about Firefox in general please join the discussion group.

            January 3rd, 2012 at 06:30

  7. David Walsh

    Is there a method by which Aurora and (present version) Firefox may be opened simultaneously? Can that be considered for the future? I wanted to tinker but don’t want to close Firefox. :)

    December 25th, 2011 at 05:45

    1. thinsoldier

      Aurora is perfectly usable for all my daily browsing/development tasks. Have been using it almost since it was first released.

      In fact, due to some glitch in my OS X profile, Aurora actually works perfectly while Firefox has a major problems.

      There’s nothing to fear with Aurora unlike the beta or nightly. But if you must you could made a separate firefox profile just for Aurora to use.

      December 27th, 2011 at 10:39

      1. Danny

        The beta will be more stable than the Aurora release by the nature of Aurora being the alpha channel

        December 28th, 2011 at 06:14

      2. Robert Nyman


        Thanks, glad you like it!

        December 30th, 2011 at 17:27

    2. Robert Nyman

      David Walsh,

      You can do that with multiple profiles for Firefox.

      December 30th, 2011 at 17:27

  8. Joe

    Running on Android and the new Aurora 11 removes the only two features that keep me on Mozilla rather than stock browser. Sync is gone now for all of my bookmarks and AdBlock Plus add-on can’t be added.

    Loosing those two features and still not being able to load flash content is quite a setback.

    Might as well just go with the stock browser.

    December 28th, 2011 at 10:00

    1. Robert Nyman

      Regarding Aurora and Android, we are trying out a new interface and technical approach to improve it. Not sure why Sync isn’t there, but to my knowledge, there is no way to remove it.

      With AdBlock Plus, I’m sure it will be updated soon.

      January 2nd, 2012 at 04:57

  9. Gio

    @Robert Nyman
    — if you talk about it doesn’t have any interface elements connected to it.

    in other browser they works,
    they will possible in next versions?

    December 31st, 2011 at 02:54

    1. Robert Nyman

      We will definitely have them, but I can’t promise in what version they will be.

      January 2nd, 2012 at 04:58

  10. Srini

    @ all, I am gonna use firefox for first time and just came to know about aurora. So which version will better suit me. Will it be useful for developers if a new person like me downloads aurora and tests it. If I download regular version can I choose to change to aurora after using regular version for some days? Any suggestions?

    January 1st, 2012 at 02:48

    1. Robert Nyman

      Yes, it’s always good if people try it out, give feedback and report back to us!

      You can download them and install them side-by-side, and then choose to use whichever one you want. If you want them running simultaneously, though, you need to set up multiple profiles, as described above.

      So, play around, test it and see what you like!
      Good luck!

      January 2nd, 2012 at 05:00

  11. OrNot

    Can anybody tell me when this issue will be fixed? Frankly, the array performance of fixfox is the worst among chrome,safari, opera and even ie9 .

    January 10th, 2012 at 23:19

    1. Robert Nyman

      I can’t give a time frame, only that it is part of all the things that are being worked on and will be prioritized accordingly.

      January 12th, 2012 at 11:53

  12. tokai

    firefox need change for mayor visual theme, most of my friend now surf with google chrome because it’s good looking, adn they don’t know about about theme add on

    January 12th, 2012 at 06:12

    1. Robert Nyman

      A lot of work, evaluation and testing goes into the major theme, and there will be some changes to it in the future.

      January 12th, 2012 at 11:54

      1. Robson Sobral

        Please, don’t make Firefox looks like Chrome!

        January 12th, 2012 at 12:08

        1. pd


          Chrome is ugly, minimalist, has no relationship to the host OS’s native applications and it’s easy to get lost between where the browser ends and content begins – so much so you’d think that was deliberate design goal.

          @tokai: poll your friends again, ask them to think past the superficial and suggest a few more reasons than looks. A browser is a complex piece of software. Maybe I’m too much of a techy but I’d be surprised if anyone consciously chose a browser based on looks alone (or just one criteria).

          January 13th, 2012 at 03:21

          1. Robson Sobral

            Minimalism is good. Chrome is ugly. The tabs take so much horizontal space and there’s no unity in its design. Safari has unity, Metro has uniy; Chrome doesn’t.

            January 13th, 2012 at 10:14

  13. Sunil

    Hi mozilla Guys,

    Please stop updating your browser so fast , you do not need to compete with chrome. Think about end users It does not make them happy as many of the extensions stop working . Please stable the current release test it first. The best release of firefox was 3.6 . End users could see the improvements in that release. It still feels slow, takes memory compared to Chrome and IE9. Please, fix the existing one before adding new one featuures in current Release.

    Please make the browser fast It still feels slow compared to others

    January 16th, 2012 at 01:51

    1. Robert Nyman


      The idea with rapid releases is to not only fix things and add features, but also make sure that end users can get a better experience today and don’t have to wait a year for a new release.

      The latest Firefox is up to 7 times faster than 3.6 and uses up to 50% less memory (more information on Firefox progress in 2011).

      Extensions that stop working is a problem, and from Firefox 10, extensions hosted at will be regarded as compatible by default.

      January 17th, 2012 at 03:19

  14. janssen kurt

    i do like new features like the improved speed and other preparations for the future but it seems like the good old days that firefox is rockstable are gone! random hangs for instance. i can’t even save files whitout firefox hanging . i hope more efford will be done to make firefox stable again…:)

    February 10th, 2012 at 13:15

    1. Jean-Yves Perrier

      This is not normal and not what most users are experiencing. I recommend you go to where they can help you in diagnosing your problem.

      February 10th, 2012 at 22:56

  15. Jordan

    What happened to @font-face in Firefox 11? It works in Chrome on Mac but in Firefox 11 on Mac OS X it no longer works.

    March 23rd, 2012 at 11:09

    1. Robert Nyman

      @font-face has been int there a long time and hasn’t changed with Aurora 11. Maybe this Stack Overflow answer helps. Please file a bug if the problem persists.

      March 23rd, 2012 at 12:02

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