Web/API/XMLHTTPRequest/XMLHttpRequest

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The XMLHttpRequest() constructor creates a new XMLHttpRequest.

For details about how to use XMLHttpRequest, see Using XMLHttpRequest.

Syntax

const request = new XMLHttpRequest();

Parameters

None.

Return value

A new XMLHttpRequest object. The object must be prepared by at least calling open() to initialize it before calling send() to send the request to the server.

Non-standard Firefox syntax

Firefox 16 added a non-standard parameter to the constructor that can enable anonymous mode (see bug 692677). Setting the mozAnon flag to true effectively resembles the AnonXMLHttpRequest() constructor described in older versions of the XMLHttpRequest specification.

const request = new XMLHttpRequest(paramsDictionary);

Parameters (non-standard)

objParameters: There are two flags you can set:

mozAnon Boolean: Setting this flag to true will cause the browser not to expose the origin and user credentials when fetching resources. Most important, this means that cookies will not be sent unless explicitly added using setRequestHeader. mozSystem Boolean: Setting this flag to true allows making cross-site connections without requiring the server to opt-in using CORS. Requires setting mozAnon: true, i.e. this can't be combined with sending cookies or other user credentials. This only works in privileged (reviewed) apps (bug 692677); it does not work on arbitrary webpages loaded in Firefox