How to determine browser window size or resolution on server side?

There is not straightforward package/method to determine the client browser resolution on server side. We can use Javascript to get the viewport document width and height. Then pass the values back via a hidden form input or ajax.

var width = $(window).width();
var height = $(window).height();

And for  getting document width and height:

var width = $(document).width();
var height = $(document).height();