XMLHttpRequestEventTarget

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨July 2015⁩.

Note: This feature is available in Web Workers, except for Service Workers.

XMLHttpRequestEventTarget is the interface that describes the event handlers shared on XMLHttpRequest and XMLHttpRequestUpload.

You don't use XMLHttpRequestEventTarget directly; instead you interact with the sub classes.