$(window).unload is not firing

Actually some browsers such as Google Chrome might block if you attempt to alert in a window unload. As a user I like this feature. Alerting every time you try to navigate away from a page sucks:

Replace the alert with a console.log or something else less intrusive to the user and the event will be happily called.

You might also want to checkout the onbeforeunload event.

as bhelm said beforeunload works for me as well.
return false on this event will invoke the browser default

are you sure you want to leave this page?

$(window).on('beforeunload', function ()
    {
        return false;
    });

jquery .on('unload',..); was not reliable working for me. i switched over to use beforeunload. just make sure you are not returning anything, or the user will get a "are you sure to leave the page"-popup.

<script type='text/javascript'>
    $(window).on('beforeunload', function(){
         console.log("beforeUnload event!");
     });
</script>