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.



The Home.banner API lets you customize a banner that appears at the bottom of the home page. You can use this API to add and remove messages from the set of messages that rotate through this banner.



Adds a message to the set of messages that rotate through the banner.


Takes an object with parameters describing the message.

Parameter Description
text The text to show in the message
icon An icon to show next to the message. Can be a URI for a local resource, or a data URI
onclick A function that will be called when the banner is clicked while this message is showing
onshown A function that will be called when this message is shown in the banner
ondismiss A function that will be called when the user dismisses this message
Return value

Returns a unique id for the message that was added.


Removes a message from the set of messages that rotate through the banner.


Takes an id for the message to remove.

Parameter Description
id The id of the message to remove
Return value



var myMessageId = Home.banner.add({
  text: "This is the text in my banner message",
  icon: "chrome://myaddon/skin/icon.png",
  onclick: function() {
    alert("Clicked on home banner!");


See also

Some demo add-ons are available on Github:

Document Tags and Contributors

Last updated by: rebloor,