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 addons.mozilla.org (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.

The NativeWindow object is only available to privileged code running on Firefox for Android, and is intended for use by Firefox for Android add-ons.


NativeWindow.menu.add() adds an item to the main menu in Firefox for Android, returning an ID for the item. To update the item, use NativeWindow.menu.update(), passing in the item's ID and a set of attributes to update.


window.NativeWindow.menu.update(menuID, options);

The ID of the item to update.
The Javascript object specifying the set of attributes to update. The current set of supported options are:
  • checkable - Boolean specifying whether the item should be checkable.
  • checked - Boolean specifying whether the item should be checked.
  • enabled - Boolean specifying whether the item should be enabled.
  • visible - Boolean specifying whether the item should be checkable.
  • name - String specifying the new text to show.


The following example adds a menu item with the label "Desktop Mode" which can be toggled.

var menuID;  
var isChecked = false;  
function addMenuItem(window) {  
  menuID = window.NativeWindow.menu.add({  
    name: "Desktop Mode",  
    icon: null,  
    checkable: true,   // specifies the toggling behavior of the item.  
    callback: function(){  
function toggleWindow(window) {  
  isChecked = !isChecked;
  window.NativeWindow.menu.update(menuID, {
   checked: isChecked   // updates the checked state of the item.  

See Also

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Last updated by: rebloor,