RegisteredContentScript is returned by a call to contentScripts.register() and represents the content scripts registered in that call.

It defines a single function unregister(), which can be used to unregister the content scripts.

Note that if this object is destroyed (for example because it goes out of scope) then the content scripts will be unregistered automatically, so you should keep a reference to this object for as long as you want the content scripts to stay registered.


Unregisters the content scripts represented by this object.

Browser compatibility

ChromeEdgeFirefoxFirefox for AndroidOpera
Basic support No No5959 No
unregister No No5959 No


This code toggles a registered content script on a browser action click:

var registered = null;

async function register() {

  registered = await browser.contentScripts.register({
    matches: ["*://*.org/*"],
    js: [{
      code: "document.body.innerHTML = '<h1>This page has been eaten<h1>'"
    runAt: "document_idle"


function toggle() {
  if (registered) {
    registered = null;
  } else {



Document Tags and Contributors

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