Performing GET request before leaving page

Question

If a GET request is made as follows

$(window).bind('beforeunload', function() {
    // GET request
});

and the page is abandoned before the GET request is completed,

will the destination server still process the request? Or will it somehow vanish?

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I would like to send a server data on beforeunload firing, but without stealing useless ms from the user.

It would be very useful if someone could help me.

Answer 1

If it is an asynchronous request then the server may process it (if it receives the request) but I don't know if you can guarantee that the request will go through before the page is unloaded or if it will be processed - this may depend on the actual web server (someone else may have more information). If you make a synchronous request, the page will wait until the request goes through and it gets back a response (so in this case, processing is guaranteed). However, this means that your browser will be locked up until that request completes, which may not be desirable.

Answer 2

In most cases yes, but it depends on the web application server. Some can detect the disconnect and stop with the request.