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

This provides a convenient way for other privileged extension scripts — such as scripts running in options pages, or scripts running in browser action or page action popups (but not content scripts) — to get direct access to the background script's scope. This enables them to access variables or call functions defined in that scope.

If the background page is an event page, the system will ensure it is loaded before calling the callback. If the add-on does not include a background page, this function sets runtime.lastError.


  function(backgroundPage) {...} // function

This API is also available as browser.runtime.getBackgroundPage() in a version that returns a promise.


function. The function is passed the following arguments:
An object representing the Window object for the background page, if there is one.

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

chrome.runtime.getBackgroundPage((page) => {;


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: Makyen, chrisdavidmills, wbamberg
 Last updated by: Makyen,