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 in secure contexts (HTTPS), in some or all supporting browsers.

The CookieChangeEvent interface of the Cookie Store API is the event type of the change event fired at a CookieStore 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 new CookieChangeEvent.

Instance properties

This interface also inherits properties from Event.

CookieChangeEvent.changed Read 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.deleted Read 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 from Event.

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

cookieStore.addEventListener("change", (event) => {
  console.log(event);
});

const one_day = 24 * 60 * 60 * 1000;
cookieStore.set({
  name: "cookie1",
  value: "cookie1-value",
  expires: Date.now() + one_day,
  domain: "example.com",
});

Specifications

Specification
Cookie Store API # CookieChangeEvent