Firefox 5 Compatibility Bump

Earlier tonight we updated compatibility information for add-ons that work with Firefox 4 to also work with Firefox 5, except in certain cases where we think the add-on may be incompatible. This coincided with the beta release of Firefox 5, though normally it would occur when the Nightly channel is promoted to Aurora, as described in the Rapid Releases Compatibility Plan.

We were able to mark 3,890 add-ons as compatible with Firefox 5. There were 256 that failed our automatic scanners either due to including binary components or using navigator.language, which was changed in Firefox 5. All affected add-on authors received an email about the compatibility update and instructions depending on whether they passed or failed.

This was our first time doing a mass compatibility bump, so please let us know your feedback on it, especially if you think something didn’t work properly.

One noteworthy issue is that some developers will receive emails saying that a previous version of their add-on has had its compatibility bumped if the latest version is already compatible. We only intended to bump the latest reviewed version of a Firefox 4 compatible add-on, along with any newer versions that haven’t been reviewed yet. This unnecessary change should be corrected for future updates.

Developers will see this process take place again in the next two weeks for the imminent Aurora 6 promotion, and then things will be on their normal track every 6 weeks.

35 comments on “Firefox 5 Compatibility Bump”

  1. Cristian wrote on

    Is there going to be Firefox 5 es-AR? Because there’s just Firefox 5 es-ES.

  2. Alan Baxter wrote on

    The bump doesn’t appear to be in effect anymore. About eleven hours ago I noticed that many of my 32 extensions that were compatible with Fx 4.0.* were now compatible with Fx 5.0. I’m pretty sure Greasemonkey was one of them. I use the Is It Compatible extension to get this info in the Add-ons Manager. An hour or two later I noticed that all of them were back to reporting Fx 4.0.*. I double-checked this just now by creating a new profile with the current Beta (5.0) and attempted to install Greasemonkey in it. “Greasemonkey could not be installed because it is not compatible with Fx 5.0.”

    1. Alan Baxter wrote on

      Seems to be working now. Thanks. I may have misremembered about Greasemonkey. It’s still at 4.0.* but many of the other extensions have been bumped to 5.*.

    2. Justin Scott (fligtar) wrote on

      Thursday night there was an error that mistakenly bumped compatibility for more add-ons than we intended to. We reverted that yesterday and then ran the real bump. That’s probably what you saw.

  3. lovinglinux wrote on

    First of all, I would like to say this is an awesome feature. Great job!

    It worked like a charm for me. However I am experiencing issues with the method that replaced navigator.language:

    I was wondering if such compatibility tests will also be performed when uploading a new version with the target version already declared in the install.rdf?

  4. Michael Kaply wrote on

    You guys also broke add-ons.

    Please fix it. Quickly.

    1. Justin Scott (fligtar) wrote on

      I don’t think that’s related to the bump.

      1. Michael Kaply wrote on

        It seems odd to me that out of all of our add-ons, only three were marked as not 5.0 compatible and those three are in this state where they can’t be downloaded.

        That’s quite a coincidence.

      2. Michael Kaply wrote on

        Specifically, in our three notes that we got saying that there were compatibility issues with these three themes, we got links to view the validation results that were all bad:

  5. jrk wrote on

    4.0 Lang Packs should not be marked as compatible with 5.0.

  6. Jack wrote on

    some addon have problem…

  7. Harsh86 wrote on

    Very cool.

  8. Kohei wrote on

    A Japanese translation of this article is here:

  9. slosd wrote on

    “We were able to mark 3,890 add-ons as compatible with Firefox 5. There were 256 that failed our automatic scanners […]”

    What’s with all the other add-ons? o.O

    1. Michael Kaply wrote on

      Only Firefox 4 compatible add-ons were marked as Firefox 5 compatible.

      1. slosd wrote on

        Ah… of course, thx.

        Although I’m still wondering why my addon wasn’t bumped. It’s compatible with Firefox 3.0 – 4.0.*
        It would be very interesting for a developer what caused his or her addon not to be automatically updated to the new version. Is there any place where I can see that information?

  10. Arbel wrote on

    Hi Justin, I have submitted my add-on on April 26, 2011, it’s already a month and it’s not reviewed yet, also I’ve not received any updates regarding that.

    Is anything wrong with that or it’s just because the queue is too long?

    The link to the add-on is for your reference.


  11. Max91 wrote on

    My addon, STS Timer (, is compatible with FF4.0, but was not bumped to 5.*. Why? I have not received any email

  12. ChrisT wrote on

    Google toolbar doesn’t work for FF 5

  13. Lucinda wrote on

    I need my roboform…….please! Any idea when it will be compatible?

  14. dokaberia wrote on

    Used fox 4 with skype, alexa now can’t skype, cant show alexa rank among other after updating to fox 5

  15. Joe wrote on

    The RealPlayer Browser Record Plug-In was not bumped. When will it be?

    1. Jorge Villalobos wrote on

      That depends entirely on the developers. If it wasn’t bumped automatically, they have to do it when it’s ready.

  16. Unkabuzz wrote on

    Does anybody know if the pinch to zoom feature working in FF5??

  17. DSM wrote on

    Can I ask why a non-essential update is released without verification that many popular updates remain compatible? Are we to sit on our thumbs while many of the key reasons why we use Firefox to begin with are shut off?

  18. lightsup55 wrote on

    Firefox 5 already? Could’ve sworn I upgraded to Firefox 4 only a few months ago.

    If my Firefox 4 add-ons work in Firefox 5, then I’ll be upgrading ASAP!

  19. anon emoose wrote on

    AVG link scanner seems to be incompatible as well
    feeling a bit exposed here 😐

  20. Katie wrote on

    I want my google toolbar! That’s all I care about because I don’t use any other add-ons. I wish I could switch back to Foxfire 4.

  21. Ross Dickson wrote on

    I miss my google toolbar

  22. Danny wrote on

    Realplayer is not compatible, I can no longer download. Is there a way for me to go back to previous version of firefox? This new version has created too many problems for me.

  23. online shopping in india wrote on

    Seems to be working now. Thanks. I may have misremembered about Greasemonkey. It’s still at 4.0.* but many of the other extensions have been bumped to 5.*.

  24. Yoron wrote on

    FF 5 Won’t work with Greasemonkey and I can’t find any workarounds either. And that sux seriously. It wored a little while, then stopped. I reinstalled and it worked a while, then disappeared in the ‘add on’ section too. Reinstalled again and restarted FF. It’s in ‘Add ons’ but i can’t install js files with it. And my old is gone from FF5. so I don’t want FF 5 any longer.

    Which mean that the sole reason for me using FF is gone, the add ons that really make it different.
    You’re doing the same mistake that M$ did here.
    And you’re going to lose users as you do it.


    1. Steven Douglas wrote on

      @Yoron – same problem here, and how frustrating. What is even MORE frustrating is that Greasemonkey MAKES ZERO MENTION of the fact that it WILL NOT WORK WITH FIREFOX 5.

      Yeah, I’m not just typing in caps. I am yelling.

  25. Prithvi wrote on

    Does Real Player Browser Record Plugin work in Firefox 4 + .. put simply, I am afraid I’ll lose the ‘download now’ add-on/plugin button facility once I upgrade from my current compatible FF 3.6.27 to 4 and above .. perhaps even the latest. Please advise till which version I should upgrade my FF till so as to keep this plugin working seamlessly and compatible.

  26. Ben wrote on

    The whole thing has been a total piece of shit since it speed up its freaking version numbers! Always troubles with add-ons when got upgraded! Shit!