CookieChangeEvent

Baseline 2025

Newly available

Since ⁨June 2025⁩, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Secure context: This feature is available only insecure contexts (HTTPS), in some or allsupporting browsers.

TheCookieChangeEvent interface of theCookie Store API is the event type of thechange event fired at aCookieStore when any cookies are created or deleted.

Note:A cookie that is replaced due to the insertion of another cookie with the same name, domain, and path, is ignored and does not trigger a change event.

Constructor

CookieChangeEvent(): Creates a newCookieChangeEvent.

Instance properties

This interface also inherits properties fromEvent.

CookieChangeEvent.changedRead only: An array listing all newly-created cookies. Note that this will exclude cookies which were created with an expiry date in the past, as these cookies are immediately deleted.
CookieChangeEvent.deletedRead only: An array listing all cookies which were removed, either because they expired or because they were explicitly deleted. Note that this will include cookies which were created with an expiry date in the past.

Instance methods

This interface also inherits methods fromEvent.

In this example when the cookie is set, the event listener logs the event to the console. This is aCookieChangeEvent object with thechanged property containing an object representing the cookie that has just been set.

cookieStore.addEventListener("change", (event) => {  console.log(event);});const oneDay = 24 * 60 * 60 * 1000;cookieStore.set({  name: "cookie1",  value: "cookie1-value",  expires: Date.now() + oneDay,  domain: "example.com",});