XMLHttpRequest: withCredentials property

The XMLHttpRequest.withCredentials property is a boolean value that indicates whether or not cross-site Access-Control requests should be made using credentials such as cookies, authentication headers or TLS client certificates. Setting withCredentials has no effect on same-origin requests.

In addition, this flag is also used to indicate when cookies are to be ignored in the response. The default is false. XMLHttpRequest responses from a different domain cannot set cookie values for their own domain unless withCredentials is set to true before making the request. The third-party cookies obtained by setting withCredentials to true will still honor same-origin policy and hence can not be accessed by the requesting script through document.cookie or from response headers.

const xhr = new XMLHttpRequest();
xhr.open("GET", "http://example.com/", true);
xhr.withCredentials = true;
xhr.send(null);