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.



Each HomeStorage object is associated with a single dataset. This object is used to save and delete data. Consumers can retreive a HomeStorage object through the HomeProvider API.

Method Overview

Promise save(in array items)
Promise deleteAll()

Item attributes

Attributes that can be specified on the items passed into save. These attributes will result in different displays when using the Home.panels API.

Attribute Type Required Description
url string yes URL associated with this item
title string no Title for the item.
description string no Description for the item.
image_url string no URL to an image associated with the item. Images are displayed in 95dp squares (95px on mdpi devices, 190px on xhdpi devices). Currently local images do not work (see bug 1004517).
filter string no Used to filter items in a dataset.
background_url string no

URL to a background image for the item.

New in Firefox 41.

background_color string no

Background color for the item, specified in hexadecimal notation. For example: #FF9500.

New in Firefox 41.



Stores an array of data items. Returns a promise that is fulfilled after the data is saved.

Promise save(
  in array items,
  in object options
An array of items to save. For performance reasons, we will throw an exception if you try to store more than 100 items at once. Additionally, a home panel view will only display 100 items at once.
(Optional) JS object holding additional configuration properties.
Attribute Type Description
replace boolean Whether or not to replace existing items.


Deletes all items associated with this dataset. Returns a promise that is fulfilled after the data is deleted.

Promise deleteAll(