Retrieves the Window object for the background page running inside the current add-on.

This provides a convenient way for other privileged add-on scripts to get direct access to the background script's scope. This enables them to access variables or call functions defined in that scope. "Privileged script" here includes scripts running in options pages, or scripts running in browser action or page action popups, but does not include content scripts.

If the background page is an event page, the system will ensure it is loaded before resolving the promise.

This is an asynchronous function that returns a Promise.


var gettingPage = browser.runtime.getBackgroundPage()



Return value

A Promise that will be fulfilled with the Window object for the background page, if there is one. If the add-on does not include a background page, the promise is rejected with an error message.

Browser compatibility

Chrome Edge Firefox Firefox for Android Opera
Basic support Yes Yes 45.0 48.0 33


Suppose a background script defines a function foo():

// background.js

function foo() {
  console.log("I'm defined in background.js");

A script running in a popup can call this function directly like this:

// popup.js

function onGot(page) {;

function onError(error) {
  console.log(`Error: ${error}`);

var getting = browser.runtime.getBackgroundPage();
getting.then(onGot, onError);


This API is based on Chromium's chrome.runtime API. This documentation is derived from runtime.json in the Chromium code.

Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.

Document Tags and Contributors

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