We are planning to deprecate the use by Firefox add-ons of the techniques described in this document.

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 instead.

Add-ons developed using these techniques might not work with multiprocess Firefox (e10s), which is already the default in Firefox Nightly and Firefox Developer Edition, and will soon be the default in Beta and Release versions of Firefox. We have documentation on making your add-ons multiprocess-compatible, but it will be more future-proof for you to migrate to WebExtensions.

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


Create UI component IDs.




Makes and/or gets a unique ID for the input.

Making an ID

const { identify } = require('sdk/ui/id');

const Thingy = Class({
  initialize: function(details) {
    let id = identify(this);

Getting an ID

const { identify } = require('sdk/ui/id');
const { Thingy } = require('./thingy');

let thing = Thingy(/* ... */);
let thingID = identify(thing);

Defining ID generator

const { identify } = require('sdk/ui/id');

const Thingy = Class(/* ... */);

identify.define(Thingy, thing => thing.guid);

object : Object
Object to create an ID for.


String : Returns a UUID by default (or domain specific ID based on a provided definition).

Document Tags and Contributors

 Contributors to this page: wbamberg
 Last updated by: wbamberg,