WebExtensions in Firefox 46

We last updated you on our progress with WebExtensions when Firefox 45 landed in Developer Edition (Aurora), and today we have an update for Firefox 46, which landed in Developer Edition last week.

While WebExtensions will remain in an alpha state in Firefox 46, we’ve made lots of progress, with 40 bugs closed since the last update. As of this update, we are still on track for a milestone release in Firefox 48 when it hits Developer Edition. We encourage you to get involved early with WebExtensions, since this is a great time to participate in its evolution.

A focus of this release was quality. All code in WebExtensions now pass eslint, and we’ve fixed a number of issues with intermittent test failures and timeouts. We’ve also introduced new APIs in this release that include:

  • chrome.notifications.getAll
  • chrome.runtime.sendMessage
  • chrome.webRequest.onBeforeRedirect
  • chrome.tabs.move

Create customizable views

In addition to the new APIs, support was added for second-level popup views in bug 1217129, giving WebExtension add-ons the ability to create customizable views.

Check out this example from the Whimsy add-on:

Create an iFrame within a page

The ability to create an iFrame that is connected to the content script was added in bug 1214658. This allows you to create an iFrame within a rendered page, which gives WebExtension add-ons the ability to add additional information to a page, such as an in-page toolbar:


For additional information on how to use these additions to WebExtensions, (and WebExtensions in general), please check out the examples on MDN or GitHub.

Upload and sign on addons.mozilla.org (AMO)

WebExtension add-ons can now be uploaded to and signed on addons.mozilla.org (AMO). This means you can sign WebExtension add-ons for release. Listed WebExtension add-ons can be uploaded to AMO, reviewed, published and distributed to Firefox users just like any other add-on. The use of these add-ons on AMO is still in beta and there are areas we need to improve, so your feedback is appreciated in the forum or as bugs.

Get involved

Over the coming months we will work our way towards a beta in Firefox 47 and the first stable release in Firefox 48. If you’d like to jump in to help, or get your APIs added, please join us on our mailing list or at one of our public meetings, or check out this wiki page.

5 comments on “WebExtensions in Firefox 46”

  1. Peter wrote on

    Nice, when will this bug fixed:

    “Duplicate add-on ID found.” ?

    1. Jorge Villalobos wrote on

      It’s not a bug, though we did make some changes for this recently. I suggest you email amo-admins AT mozilla DOT org and explain your situation.

    2. Kumar McMillan wrote on

      If you’re using jpm, are you fully up to date? What you described is a known bug that was fixed in jpm

  2. Michel Wilhelm wrote on

    WebExtension is a universal extension?

    1. Knight Yoshi wrote on

      WebExtensions is an API to make Firefox extensions (add-ons) that are easier to port to and from Chrome. It imitates Chrome’s extension API.