The set() method of the cookies API sets a cookie containing the specified cookie data. This method is equivalent to issuing an HTTP Set-Cookie header during a request to a given URL.

The call succeeds only if you include the "cookies" API permission in your manifest.json file, as well as host permissions for the given URL specified in its manifest. The given URL also needs the necessary permissions to create a cookie with the given parameters.

This is an asynchronous function that returns a Promise.


var setting = browser.cookies.set(
  details               // object


An object containing the details of the cookie you wish to set. It can have the following properties:
A string representing the domain of the cookie. If omitted, the cookie becomes a host-only cookie.
A number that represents the expiration date of the cookie as the number of seconds since the UNIX epoch. If omitted, the cookie becomes a session cookie.
A string representing the first-party domain with which the cookie to will be associated. This property must be supplied if the browser has first-party isolation enabled. See First-party isolation.
A boolean that specifies whether the cookie should be marked as HttpOnly (true), or not (false). If omitted, it defaults to false.
A string representing the name of the cookie. If omitted, this is empty by default.
A string representing the path of the cookie. If omitted, this defaults to the path portion of the URL parameter.
A boolean that specifies whether the cookie should be marked as secure (true), or not (false). If omitted, it defaults to false.
A string representing the ID of the cookie store in which to set the cookie. If omitted, the cookie is set in the current execution context's cookie store by default.
A string representing the request-URI to associate with the cookie. This value can affect the default domain and path values of the created cookie. If host permissions for this URL are not specified in the manifest file, the method call will fail.
A string representing the value of the cookie. If omitted, this is empty by default.

Return value

A Promise that will be fulfilled with a cookies.Cookie object containing details about the cookie that's been set. If the call fails for any reason, the promise will be rejected with an error message.

Browser compatibility

ChromeEdgeFirefoxFirefox for AndroidOpera
Basic support Yes Yes451481 Yes

1. Before version 56, this function did not modify cookies in private browsing mode. From version 56 onwards this is fixed.


This example sets a cookie for the document hosted by the currently active tab:

var getActive = browser.tabs.query({active: true, currentWindow: true});

function setCookie(tabs) {
    url: tabs[0].url,
    name: "favourite-colour",
    value: "red"

Example extensions


This API is based on Chromium's chrome.cookies API. This documentation is derived from cookies.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, kmaglione
 Last updated by: wbamberg,