When the user installs or upgrades an add-on, the browser may warn the user about any particularly powerful permissions that the add-on has requested. Not all permissions result in warnings, and this behavior is not standardised across browsers.

Given the ID of an add-on, this function returns the permission warnings for it as an array of strings.

This API requires the "management" API permission.

This is an asynchronous function that returns a Promise.


var gettingWarnings =
  id                  // string


string. ID of the add-on whose permission warnings you want to retrieve.

Return value

A Promise that will be fulfilled with an array of strings, each of which contains the text of a permission warning.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxOperaSafariFirefox for Android
getPermissionWarningsByIdChrome Full support YesEdge Full support 79Firefox No support NoOpera Full support YesSafari No support NoFirefox Android No support No


Full support  
Full support
No support  
No support


Log the permission warnings for the add-on whose ID is "my-add-on":

var id = "my-add-on";

function gotWarnings(warnings) {
  for (warning of warnings) {

var gettingWarnings =;

This API is based on Chromium's API. This documentation is derived from management.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.