How to know when AJAX request was initiated within webpage?

I’ve a webpage which consists Javascript files of other domains as I use third party tools, what I want to do is whenever an javascript function initiates an AJAX request

how can I access it’s information like the URL, request type etc… using another thread of Javascript?

Push the F12 key in your browser to see the developer tools.
The Network tab contains a list of all requests made by the webpage.

No, I know that, but I want to access that information using Javascript, I’ve edited the question please check again.

You may be able to write a browser extension that could do what you want.

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You might monkey patch the native XMLHttpRequest to log, for example, the arguments passed to .open() like so:

// Keep a reference to the original `.open()` method
var open =

// Add your own logic = function () {
  // Apply the original method
  open.apply(this, arguments)

// Some 3rd party code opens an XHR...
var xhr = new XMLHttpRequest()'GET', 'data.json') // will log ['GET', 'data.json']

This will, however, not work if that XHR is getting opened in a different thread (such as from a web worker) – it modifies the XMLHttpRequest.prototype for the current thread only.


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