Check with jquery if div has overflowing elements

You actually don't need any jQuery to check if there is an overflow happening or not. Using element.offsetHeight, element.offsetWidth , element.scrollHeight and element.scrollWidth you can determine if your element have content bigger than it's size:

if (element.offsetHeight < element.scrollHeight ||
    element.offsetWidth < element.scrollWidth) {
    // your element have overflow
} else {
    // your element doesn't have overflow
}

See example in action: Fiddle

But if you want to know what element inside your element is visible or not then you need to do more calculation. There is three states for a child element in terms of visibility:

If you want to count semi-visible items it would be the script you need:

var invisibleItems = [];
for(var i=0; i<element.childElementCount; i++){
  if (element.children[i].offsetTop + element.children[i].offsetHeight >
      element.offsetTop + element.offsetHeight ||
      element.children[i].offsetLeft + element.children[i].offsetWidth >
      element.offsetLeft + element.offsetWidth ){

        invisibleItems.push(element.children[i]);
    }

}

And if you don't want to count semi-visible you can calculate with a little difference.

Partially based on Mohsen's answer (the added first condition covers the case where the child is hidden before the parent):

jQuery.fn.isChildOverflowing = function (child) {
  var p = jQuery(this).get(0);
  var el = jQuery(child).get(0);
  return (el.offsetTop < p.offsetTop || el.offsetLeft < p.offsetLeft) ||
    (el.offsetTop + el.offsetHeight > p.offsetTop + p.offsetHeight || el.offsetLeft + el.offsetWidth > p.offsetLeft + p.offsetWidth);
};

Then just do:

jQuery('#parent').isChildOverflowing('#child');

I had the same question as the OP, and none of those answers fitted my needs. I needed a simple condition, for a simple need.

Here's my answer:

if ($("#myoverflowingelement").prop('scrollWidth') > $("#myoverflowingelement").width() ) {
  alert("this element is overflowing !!");
}
else {
 alert("this element is not overflowing!!");
}

Also, you can change scrollWidth by scrollHeight if you need to test the either case.