This is an archived page. It's not actively maintained.



Support for extensions using XUL/XPCOM or the Add-on SDK was removed in Firefox 57, released November 2017. As there is no supported version of Firefox enabling these technologies, this page will be removed by December 2020.

Add-ons using the techniques described in this document are considered a legacy technology in Firefox. Don't use these techniques to develop new add-ons. Use WebExtensions instead. If you maintain an add-on which uses the techniques described here, consider migrating it to use WebExtensions.

Starting from Firefox 53, no new legacy add-ons will be accepted on (AMO) for desktop Firefox and Firefox for Android.

Starting from Firefox 57, only extensions developed using WebExtensions APIs will be supported on Desktop Firefox and Firefox for Android.

Even before Firefox 57, changes coming up in the Firefox platform will break many legacy extensions. These changes include multiprocess Firefox (e10s), sandboxing, and multiple content processes. Legacy extensions that are affected by these changes should migrate to use WebExtensions APIs if they can. See the "Compatibility Milestones" document for more information.

A wiki page containing resources, migration paths, office hours, and more, is available to help developers transition to the new technologies.



Provides helper functions for working with platform internals like frames and browsers.


Module exports create function that takes the nsIDOMDocument of a privileged document and creates a browser element in its documentElement:

let { open } = require('sdk/window/utils');
let { create } = require('sdk/frame/utils');
let window = open('data:text/html,Foo');
let frame = create(window.document);

Optionally create can be passed set of options to configure created frame even further.

Execution of scripts may easily be enabled:

let { open } = require('sdk/window/utils');
let { create } = require('sdk/frame/utils');
let window = open('data:text/html,top');
let frame = create(window.document, {
  uri: 'data:text/html,<script>console.log("running");</script>',
  allowJavascript: true



create(document, options)

Creates a XUL browser element in a privileged document.


document : nsIDOMDocument

options : object
Optional options:

Name Type  
type String

String that defines access type of the document loaded into it. Defaults to "content". For more details and other possible values see documentation on MDN

uri String

URI of the document to be loaded into the new frame. Defaults to about:blank.

remote Boolean

If true separate process will be used for this frame, and all the following options are ignored.

allowAuth Boolean

Whether to allow auth dialogs. Defaults to false.

allowJavascript Boolean

Whether to allow Javascript execution. Defaults to false.

allowPlugins Boolean

Whether to allow plugin execution. Defaults to false.


frame : The new browser element.