Default Compatibility is Coming and Your Help is Needed!

All add-ons will be made compatible by default in the upcoming Firefox 10 release, so it’s crunch time for testing them in Beta, Aurora, and Nightly. With default compatibility, you can expect to see less of the incompatible add-ons dialog, and more of your add-ons should just work.

If you are a Firefox developer, support professional, or contributor, your help is critical—if you think there might be a compatibility issue in any of the release channels, please file a bug here so we can take action right away if needed.

In general, it would be super helpful for everyone to install the Add-on Compatibility Reporter and let us know through the reporter if your add-ons are working properly.

Your help is greatly appreciated!

52 comments on “Default Compatibility is Coming and Your Help is Needed!”

  1. Michael wrote on

    How is determined if an add-on is incompatible with a new Firefox version? By reports via the Compatibility Reporter? If so, do you just say “if at least 10 users reported that an add-on is not compatible it is not compatible”?

    1. Caspy7 wrote on

      I know there are a combination of ways that an addon will get marked incompatible. I don’t remember seeing Compatibility Reporter reports as one of them (maybe it was), but it would make sense for those using pre-release builds. After the fact reports would be helpful, but undesirable.
      I *think* one of the major components here is automatic code checking which is looking for code which is incompatible based on changes to the newest version of the browser (i.e. Firefox 10 stopped supporting XYZ way of doing things).
      I know that all addons with binary components will be marked incompatible.

      You can see more here:

    2. Jorge Villalobos wrote on

      To add to what Caspy7 said, there’s a subsection dedicated to it: We will have a few different data sources to find out about incompatible add-ons, and we will verify these situations when possible. There may be cases where we flag an add-on as incompatible based on compatibility feedback alone, but those cases should be rare and only in situations where a big portion of users are affected.

  2. HenryHD wrote on

    im using Nighlty UX 12.0a1, and ive realized most addons are compatible without the addon compatibilty reporter, so yeah thumbs up Firefox.

  3. ilija wrote on

    Any chance using the Windows Driver Kit (WDK) use to be DDK for compiling, and linking Firefox with the system runtime msvcrt.dll instead of Visual Studio 8.0 runtime msvcrt80.dll that should speed up start-up time as the system runtime is loaded at boot?
    there’s a nice article about it here:

    or do a simple google search

    ps. I’ve been using the beta channel for some time now and reported all of the (non)working add-ons I have, it’s interesting that some old add-ons (abandoned with Firefox 1.0/2.0 a few games like mines, cards and tetris) are working fine while some new ones (Adobe’s Acrobat integration for example) just don’t.

  4. lifemare wrote on

    Not sure i like this feature.
    Would rather Firefox just had an easy native option to disable compatibility checks.
    Otherwise you’re making the whole addon installation process a lot less safer and unreliable.
    Is this one of those Chrome-induced changes? Does Firefox need to dumb down everything to become competitive?
    A faster simpler addon installation process is not what users want, if it’s ridden with bugs, is it?

    When installing an addon i love knowing beforehand that it might be incompatible.
    It promotes caution and instigates you to test those addons before commiting to any other browser changes.

    Imagine you’re a new user (or an old user on a new computer) installing stuff left and right on a fresh profile, three year old addons together with recent ones, unknowingly.
    How clean and trustworthy do you imagine such a configuration would be?
    Sounds like a recipe for disaster if you ask me.

    If you’re commited to this feature, at the very least bundle the Compatibility Reporter options with Firefox 10.

    But hey, i hope i’m very wrong here….

    1. nimd4 wrote on

      Very few add-ons are reviewed/approved by Mozilla, compared to the existing numbers. By installing/using add-ons, browser/computer security can be compromised (malicious and/or accidentally malicious add-ons). It’s better that there’s a whole procedure associated with them, imo. =)

      1. Jorge Villalobos wrote on

        The 25/75 stat is thrown around a lot, but that refers to add-on installations, not amount of add-ons. There are definitely more add-ons listed on AMO than distributed elsewhere, as far as I know. Also, that number was brought up precisely to justify the actions we took with Firefox 8, to give users more control of externally-installed add-ons. We haven’t measured the impact it has had on users of Firefox 8 and above, and I think that’s an important thing to know before continuing with a discussion that could potentially change the whole way we deal with add-ons and our developer community.

  5. David wrote on

    The Firefox 9.01 for Mac upgrade is annoying. Tabs lock on active websites, requiring entering bookmarks to bring them back to the screen.

    1. Amy Tsay wrote on

      Hi David, have you tried for help on your issue?

  6. Carolyn wrote on

    Lightning is the most wonderful add-on and to have had it disabled with no warning on updating to Thunderbird 9.0.1 is dire. All my reminders, engagements and forward planning events are gone, Gone, GONE. I’m devastated.

    1. Petia wrote on

      Same thing for me: not only does upgrading TB disable your add-ons, but it does so silently, which is unacceptable. In the end you just waste time uninstalling it to reinstall an older version.
      This, as well as version numbering, is ridiculous (the list of changes between TB 8 and TB 9 would be worth a 8.0.x numbering change, and this comment applies to most recent Firefox and TB versions). Of course some add-on developers can’t keep up with the inflation. At the current rate, I expect Firefox 22 in two years (no, it’s sadly not a joke).
      I hope your new add-on policy will be implemented in all mozilla products. And I hope these untested add-ons will not crash too often. Otherwise I’ll switch to truly dependable software, seeded to external developers a couple of months before their release, and incorporating true advances that make the benefit to the user larger than the cost (relearning, dropping incompatible tools, etc).

  7. frans.garus sintus wrote on

    i’m interest in using mozilla firefox, bravo

  8. Usman wrote on

    i,m using mozila but most of sites it said your certificate is not valid?plz tell how i provide you valid certificate?

    1. Jorge Villalobos wrote on

      Usman, I recommend that you visit our support site for this kind of problem.

  9. George Hazard wrote on

    Compatibility still not done even after Firefox 10 upgrade for
    Kaspersky Virtual Keyboard
    Kaspersky URL Advisor
    Kaspersky Anti Banner
    When will these become compatible?

    1. Amy Tsay wrote on

      Hi George, add-ons with binary components are not compatible by default, so you will need to wait for Kaspersky to be updated.

  10. John Nagle wrote on

    “Default compatibility”, hah! My “Ad Limiter” add-on now displays the message on AMO: “Not available for Firefox 10.0”.

    And don’t say “go to the support site”. The support site sends you here. See:

    1. Jorge Villalobos wrote on

      I’m looking at your listing on AMO and all I see is a message that says “May be incompatible with Firefox 10.0”. I can install the add-on without any problems on 10.
      What exactly are you complaining about?

      1. John Nagle wrote on

        This is a screen shot showing what I’m complaining about.

        which is a screenshot of

        Note the words in bright red: “Not available for Firefox 10.0”.

        This is seen when running Firefox 10.0. If I view the page with Google Chrome, that message is not displayed. So what message you see varies with the browser, and perhaps the browser version.

        1. Jorge Villalobos wrote on

          I was looking at the page with Firefox 10 Beta. I just tested again using the release version and saw the same thing in the screenshot. I filed this bug for it.

          Thanks for the report.

          1. Jorge Villalobos wrote on

            Hmm, it turns out to be more than that. AMO shows a different message if I have the Add-on Compatibility Reporter extension installed, as I do in my Beta profile. So yes, AMO in general is showing those ugly warnings in the screenshot. There is a plan to fix this soon, but at the moment the best way to remove them is to go to the Developer Hub and change the maxVersion of your latest version. There’s no need to upload a new file.

            This is a problem with AMO and not the default to compatible feature per-se. Sorry for the confusion.

          2. John Nagle wrote on

            The bug report you filed was closed within five minutes as “WORKSFORME”. I uploaded the screen shot to Bugzilla and pointed out that it fails in the release version of Firefox 10.

            I’ve adjusted the maximum version on the add-on in question from 9 to 10, which makes the message go away until Firefox 11. Hopefully AMO will be fixed before Firefox 11 comes out.

            The add-on compatibility treadmill needs a redesign. The business of packaging the Jetpack SDK with the add-on makes compatibility harder to achieve, not easier. The Jetpack top end, the API used by add-ons, doesn’t change much, while the bottom end is more tied the Firefox version. If the SDK were part of Firefox, and there was a commitment not to remove features from the API, we wouldn’t have to deal with this headache at all.


  11. Dharam Veer Sharma wrote on

    Hope FF 10 removes the problem of incompatible addons.

  12. BrianZ wrote on

    Mozilla’s statement that “All add-ons will be made compatible by default in the upcoming Firefox 10 release” seems like a cruel joke to me. I didn’t believe it when I first read it, and I don’t believe it now. Saying so, doesn’t make it true, and from my perspective it only makes Mozilla look bad. While it might be a good attention-getter for developers to see, it only seems to create unrealistic expectations and disappointment for ordinary users like me who experience just the opposite.

    When I first went to install FF10, it warned me that four of my current add-ons were not compatible, so it immediately proved that statement wrong. Also proven wrong is the additional statement that “you can expect to see less of the incompatible add-ons dialog, and more of your add-ons should just work”, because I had fewer incompatibilities with the last few updates to Firefox than with FF10, and now I have more incompatible add-ons, and they are important ones to me that I am not willing to give up. One of them was upgraded and made compatible yesterday, but I still have three on the list, including at least one that is critical for my safety and security – my Norton Toolbar, and that has been compatible with many previous updates, but not FF10.

    I don’t know what other users are experiencing, but for me, things seem to be getting worse, not better, in terms of add-on compatibility. I guess somebody has to tell the emperor about his new clothes.

    1. Jorge Villalobos wrote on

      You’re correct in that not all add-ons will be made compatible by default. That’s a misstatement on our part because there are exceptions. The compatible by default feature excludes: add-ons with binary XPCOM components (probably the ones you’re talking about since you mentioned Norton Toolbar), add-ons that have their compatibility set to less than Firefox 4, and add-ons that are repeatedly reported to us as incompatible, which we add to a compatibility override list.

      I can tell you that, contrary to your particular experience, our compatibility story will improve significantly because of this feature. The majority of add-ons qualify for it, so there are millions of users who are now benefiting from this. Granted, add-ons with binary XPCOM components still amount for a big chunk of add-on usage out there. We try our best to get developers to make their add-ons compatible with enough anticipation, but it is mostly out of our hands.

  13. Mike Palmer wrote on

    I am still using version 3.6.26 because it is the last version I know that lets me use my Adobe pdf converter. Why has Firefox eliminated this add-on? It is a key tool in my work.
    If you fix that problem, I will upgrade. Until then, I’m slogging along with the earlier version.

  14. amar wrote on

    i am using a download manger IDM . the earlier version befor updating to version 9. the addon IDMCC is not compatible to browser. is there any thing can done to solve this problem apart from reinstalling the softwer.

    1. ramez wrote on

      you should update IDM to version 6.08 to work with firefox 9 and 10

      1. Jorge Villalobos wrote on

        That doesn’t depend on us. And the latest versions of IDM should work in new versions of Firefox. You can look on their official site.

  15. osimen samson wrote on

    I LoVe mozilla firefox pls I want to download it to my Blackberry Bold

  16. ankit wrote on

    my IDM add on “IDM CC 6.7” is disabled by the firefox pls help

  17. Tony Mechelynck wrote on

    Well, I have the opposite case: the “Duplicate This Tab” extension does not enjoy default-to-compatible (its maxVersion is too low I think, but barely; maybe its maintainer has gone AWOL?) but it should, at least in SeaMonkey (I’ve been told the SeaMonkey and Firefox tabbrowsers are somewhat different). I use it with no problems in SeaMonkey 2.10a1 nightlies (the current trunk).

    1. Jorge Villalobos wrote on

      I was able to install it just fine in Firefox 10, no warnings at all. AMO still says that it’s incompatible, but that’s something that needs to be fixed on the site.

  18. Dr Philip J Brown wrote on

    Just installed the Thunderbird 10 edition: cannot send e-mails any more!!! Any ideas, please?

    1. Jorge Villalobos wrote on

      Try looking for help in the Mozilla Messaging support site.

  19. yves wrote on

    bonjour,la Google Toolbar for firefox 7.1.20110316w ne fonctionne pas sous Firefox 10.1,c’est à mon avis la plus pratique,c’esr désolant!malgré tout,j’arrive à obtenir la traduction,ce qui est le plus important pour moi cordialement.

    1. Jorge Villalobos wrote on

      The Google Toolbar was discontinued by Google. See this announcement for more details.

  20. elo wrote on

    50% of add-ons for SeaMonkey (and Lightning in SeaMonkey) just can not be installed because they are “incompatible with Seamonkey 2.7.2” So I wanted to try to make my own add-on.
    I have just followed a tutorial and I have stopped on step 1, because Add-on Builder Helper cannot be installed because IT IS NOT COMPATIBLE WITH SEAMONKEY 2.7.2
    I am very frustrated. 🙁

    1. Amy Tsay wrote on

      Hi elo, the Firefox Add-on SDK and online Add-on Builder do not currently support Seamonkey, nor is any official support planned. We are currently considering making changes that will make it possible to create add-ons for Mozilla-based applications other than Firefox, but this work has not been finished.

  21. Kevin Golding wrote on

    HI Folks,
    You are probably already working on fixes but after I downloaded the most recent Java update many websites are now not functioning properly in Firefox. Some financial sites like my bank are now “file not found” and others don’t format correctly. I’ve had to go back to using Internet Explorer after using Firefox exclusively for years.

  22. ramez wrote on

    I love firefox BEST browser everrrrrrrrrrrrrrrrrrrrrrrrrr

  23. Kubilay Donmez wrote on

    My laptop has fingerprint sensor and it’s working with a program which is called DigitalPersona Personal to sign in by using fingerprint instead of typing the characters one by one in some password required sites. The ex-versions of firefox were working with this program properly, but now unfortunately not.. Is it possible to adjust this version according to use this feature??

    1. Jorge Villalobos wrote on

      You should contact whoever develops this software and ask them if there is a compatible version, or any workarounds. If nothing else works, there are ways to install old versions of Firefox so that it works. Though I’m not sure that updating Firefox is why your program doesn’t work anymore…

  24. giraud wrote on

    Trés bon navigateur , me rappelle Netscape que j’ai peu connu malheureusement 🙁

  25. K. Feiler wrote on

    I would like to help you out with “add ons” info, but do not know what is “ALPHA” & “BETA” users means in the downloads cautions…. As in “For ALPHA & BETA USERS ONLY”…

    1. Jorge Villalobos wrote on

      Here’s a brief explanation on Wikipedia. In short, it means that these are test versions and can have some software defects. These defects can be noticeable in the alpha (which we call Aurora), but less so in the Beta.

  26. guilmot Danielle wrote on

    pouvez vous m’aidez , car depuis quelques temps j’emploie la version de firefox 10.0.2 et j’ai adobe flash players qui n’arrète pas de planter c’est affreux voici un lien vers lequel firefox plante et pourtant je viens de faire la mise a jour d’adobe flash players , je suis désolée de ne pas parler anglais , sorry no speack english ,e
    good evening
    can you help me, because for some time I use firefox version 10.0.2 and I have adobe flash players that do not stop to plant it’s awful here is a link which firefox plant http://www and yet I’ve just updated adobe flash players, I’m sorry for not speaking English thank you kindly help me ; bye

  27. Anna wrote on

    Not particularly an add-on problem, but I’m running Firefox 10.0.1 on a 1.83 Intel Mac, with OS 10.6.8, and Google Reader is totally messed up. the top 1.5 inches of the screen are covered by the toolbars, and hiding the toolbars doesn’t help. So I can’t use the next button, or any of the menu options usually at the top of the screen. Not having this problem on my MacBook Pro at work.

  28. subrajit wrote on


    I am using mozila 10.0.2 it is crashing every 15 minuites and CPU utilization goes 50% and memory also became very high and showing some stacktrace.js script error please can any one help me in this regards.

    Thank you

    1. Jorge Villalobos wrote on

      Please visit our support site for help.

  29. Joe wrote on

    Hi, I have FF 10.0.2 installed, the plugins worked fine. However, after I updated Adobe Acrobat and Silverlight plugin, they automatically disabled by FF, there are options to enable them or remove them, but nothing happened. It says they have been removed, but when check again, they remain disabled in the plugin list, could you please let me know how to get the above two issues resolved? Many thanks!