Add-ons Update – Week of 2016/01/06

I post these updates every 3 weeks to inform add-on developers about the status of the review queues, add-on compatibility, and other happenings in the add-ons world.

The Review Queues

In the past 3 weeks, 1801 add-ons were reviewed:

  • 1679 (93%) were reviewed in less than 5 days.
  • 25 (1%) were reviewed between 5 and 10 days.
  • 97 (5%) were reviewed after more than 10 days.

There are 471 listed add-ons awaiting review, and 6 unlisted add-ons awaiting review.

If you’re an add-on developer and would like to see add-ons reviewed faster, please consider joining us. Add-on reviewers get invited to Mozilla events and earn cool gear with their work. Visit our wiki page for more information.

Firefox 44 Compatibility

This compatibility blog post is live. The bulk compatibility validation should be run in the coming weeks.

As always, we recommend that you test your add-ons on Beta and Firefox Developer Edition to make sure that they continue to work correctly. End users can install the Add-on Compatibility Reporter to identify and report any add-ons that aren’t working anymore.

Extension Signing

The wiki page on Extension Signing has information about the timeline, as well as responses to some frequently asked questions. The current plan is to remove the signing override preference in Firefox 44.


Electrolysis, also known as e10s, is the next major compatibility change coming to Firefox. In a nutshell, Firefox will run on multiple processes now, running content code in a different process than browser code.

This is the time to test your add-ons and make sure they continue working in Firefox. We’re holding regular office hours to help you work on your add-ons, so please drop in on Tuesdays and chat with us!


If you read the post on the future of add-on development, you should know there are big changes coming. We’re investing heavily on the new WebExtensions API, so we strongly recommend that you start looking into it for your add-ons. You can track progress of its development in

We will be talking about development with WebExtensions in the upcoming FOSDEM. Come hack with us if you’re around!

8 comments on “Add-ons Update – Week of 2016/01/06”

  1. Tony wrote on

    I submitted my add-on, Cookie Monster, over a month ago and am still number 47 in the queue. This does not seem to jive with the statistics you mention. Moreover, I received a poor review, as the user was speculating about my add-on being suspicious because it has been in the queue so long.

    Can I please receive some feedback as to why my add-on has been in the review queue for such a long time?


    1. Jorge Villalobos wrote on

      Followed up by email.

      1. Harald wrote on

        Is it possible to publish (parts of) your anwser here at your blog? Because I’m also interessed how your statistics fit to the things I’ve observed.
        It seems that the queue is no FIFO queue but sorted by some metrics (like the number of users/downloads)?


        1. Jorge Villalobos wrote on

          The queues are sorted strictly by submission time, but they are not reviewed in strict order. Many reviews are flagged for admin review, usually because they have minified or obfuscated code, or binary components, but also because of complexity or other special situations. The majority of add-ons stuck in the queue have this problem, and there are only a couple of active admin reviewers working on them, part time. We’ve been trying to increase our admin review capacity, but progress has been slow.

          The other add-on submissions should be handled relatively quickly, though sometimes there are some easy reviews that regular reviewers miss and end up in the longer waiting times section of the queues, where reviewers just assume they are difficult to do and skip them.

          There are a few things we’re doing to simplify the system and encourage reviewers to take on harder reviews, but that also takes time. We know this is a big problem, though, and we’re attacking it on several fronts.

        2. Ping wrote on

          Is it possible to publish my addon quickly?

          I have waited for more than two weeks.

          Thank you.

  2. Laurentiu wrote on

    Hi Jorge,

    Please help us developers and extend the xpinstall.signatures.required option to Firefox 44 too.

    There’s still a bug on the automated signing API via JPM that was opened 3 weeks ago without a fix yet:

    Have been doing manual submissions and going through reviews/signing for the past few months now.


  3. Mike wrote on

    Question about the extension signing situation: I read a forum post on here awhile back (apparently by a Mozilla admin) saying that down the road, they are planning to separate the review requirement from the extension signing process; this is ideal for our situation, because I’m developing extensions for internal use (mostly content scripts to improve accessibility), and I know they wouldn’t pass the automated review (as they use innerHTML etc.). Honestly, this new demand threw us for a loop, to the point where management is considering switching to Chrome (sorry for the 6-letter word, LOL). So what’s the status on that, if you don’t mind me asking? Is Mozilla still planning to change the requirement for a code review, or was that guy way out in left field somewhere? Thanks in advance.

    1. Jorge Villalobos wrote on

      You can submit add-ons for signing now without going through manual code review. Pretty much every submission is being accepted, and some will be reviewed post-approval if the reviewer team deems it appropriate.