[javascript] How to capture the browser window close event?

I want to capture the browser window/tab close event. I have tried the following with jQuery:

jQuery(window).bind(
    "beforeunload", 
    function() { 
        return confirm("Do you really want to close?") 
    }
)

But it works on form submission as well, which is not what I want. I want an event that triggers only when the user closes the window.

For a cross-browser solution (tested in Chrome 21, IE9, FF15), consider using the following code, which is a slightly tweaked version of Slaks' code:

var inFormOrLink;
$('a').live('click', function() { inFormOrLink = true; });
$('form').bind('submit', function() { inFormOrLink = true; });

$(window).bind('beforeunload', function(eventObject) {
    var returnValue = undefined;
    if (! inFormOrLink) {
        returnValue = "Do you really want to close?";
    }
    eventObject.returnValue = returnValue;
    return returnValue;
}); 

Note that since Firefox 4, the message "Do you really want to close?" is not displayed. FF just displays a generic message. See note in https://developer.mozilla.org/en-US/docs/DOM/window.onbeforeunload

For a solution that worked well with third party controls like Telerik (ex.: RadComboBox) and DevExpress that use the Anchor tags for various reasons, consider using the following code, which is a slightly tweaked version of desm's code with a better selector for self targeting anchor tags:

var inFormOrLink;
$('a[href]:not([target]), a[href][target=_self]').live('click', function() { inFormOrLink = true; });
$('form').bind('submit', function() { inFormOrLink = true; });

$(window).bind('beforeunload', function(eventObject) {
    var returnValue = undefined;
    if (! inFormOrLink) {
        returnValue = "Do you really want to close?";
    }
    eventObject.returnValue = returnValue;
    return returnValue;
});

Maybe just unbind the beforeunload event handler within the form's submit event handler:

jQuery('form').submit(function() {
    jQuery(window).unbind("beforeunload");
    ...
});

My Issue: The 'onbeforeunload' event would only be triggered if there were odd number of submits(clicks). I had a combination of solutions from similar threads in SO to have my solution work. well my code will speak.

<!--The definition of event and initializing the trigger flag--->


$(document).ready(function() {
  updatefgallowPrompt(true);
  window.onbeforeunload = WarnUser; 
}

function WarnUser() {
  var allowPrompt = getfgallowPrompt();
  if(allowPrompt) {
    saveIndexedDataAlert();
    return null;
  } else {
    updatefgallowPrompt(true);
    event.stopPropagation
  }
}

<!--The method responsible for deciding weather the unload event is triggered from submit or not--->
function saveIndexedDataAlert() {
  var allowPrompt = getfgallowPrompt();
  var lenIndexedDocs = parseInt($('#sortable3 > li').size()) + parseInt($('#sortable3 > ul').size());

  if(allowPrompt && $.trim(lenIndexedDocs) > 0) {
    event.returnValue = "Your message";
  } else {
    event.returnValue = "   ";
    updatefgallowPrompt(true);
  }
}

<!---Function responsible to reset the trigger flag---->
$(document).click(function(event) {  
  $('a').live('click', function() { updatefgallowPrompt(false); });
});

<!--getter and setter for the flag---->
function updatefgallowPrompt (allowPrompt){ //exit msg dfds
  $('body').data('allowPrompt', allowPrompt);   
}   

function getfgallowPrompt(){        
  return $('body').data('allowPrompt'); 
}

I used Slaks answer but that wasn't working as is, since the onbeforeunload returnValue is parsed as a string and then displayed in the confirmations box of the browser. So the value true was displayed, like "true".

Just using return worked. Here is my code

var preventUnloadPrompt;
var messageBeforeUnload = "my message here - Are you sure you want to leave this page?";
//var redirectAfterPrompt = "http://www.google.co.in";
$('a').live('click', function() { preventUnloadPrompt = true; });
$('form').live('submit', function() { preventUnloadPrompt = true; });
$(window).bind("beforeunload", function(e) { 
    var rval;
    if(preventUnloadPrompt) {
        return;
    } else {
        //location.replace(redirectAfterPrompt);
        return messageBeforeUnload;
    }
    return rval;
})

Unfortunately, whether it is a reload, new page redirect, or browser close the event will be triggered. An alternative is catch the id triggering the event and if it is form dont trigger any function and if it is not the id of the form then do what you want to do when the page closes. I am not sure if that is also possible directly and is tedious.

You can do some small things before the customer closes the tab. javascript detect browser close tab/close browser but if your list of actions are big and the tab closes before it is finished you are helpless. You can try it but with my experience donot depend on it.

window.addEventListener("beforeunload", function (e) {
  var confirmationMessage = "\o/";
  /* Do you small action code here */
  (e || window.event).returnValue = confirmationMessage; //Gecko + IE
  return confirmationMessage;                            //Webkit, Safari, Chrome
});

https://developer.mozilla.org/en-US/docs/Web/Reference/Events/beforeunload?redirectlocale=en-US&redirectslug=DOM/Mozilla_event_reference/beforeunload

If your form submission takes them to another page (as I assume it does, hence the triggering of beforeunload), you could try to change your form submission to an ajax call. This way, they won't leave your page when they submit the form and you can use your beforeunload binding code as you wish.

jQuery(window).bind(
                    "beforeunload",
                      function (e) {
                          var activeElementTagName = e.target.activeElement.tagName;
                          if (activeElementTagName != "A" && activeElementTagName != "INPUT") {
                              return "Do you really want to close?";
                          }
                      })

As of jQuery 1.7, the .live() method is deprecated. Use .on() to attach event handlers. Users of older versions of jQuery should use .delegate() in preference to .live()

$(window).bind("beforeunload", function() {
    return true || confirm("Do you really want to close?"); 
}); 

on complete or link

$(window).unbind();

Perhaps you could handle OnSubmit and set a flag that you later check in your OnBeforeUnload handler.

My answer is aimed at providing simple benchmarks.

HOW TO

See @SLaks answer.

$(window).on("beforeunload", function() { 
    return inFormOrLink ? "Do you really want to close?" : null; 
})

How long does the browser take to finally shut your page down?

Whenever an user closes the page (x button or CTRL + W), the browser executes the given beforeunload code, but not indefinitely. The only exception is the confirmation box (return 'Do you really want to close?) which will wait until for the user's response.

Chrome: 2 seconds.
Firefox: 8 (or double click, or force on close)
Edge: 8 (or double click)
Explorer 11: 0 seconds.
Safari: TODO

What we used to test this out:

• A Node.js Express server with requests log
• The following short HTML file

What it does is to send as many requests as it can before the browser shut downs its page (synchronously).

<html>
<body>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
    <script>
    function request() {
        return $.ajax({
            type: "GET",
            url: "http://localhost:3030/" + Date.now(),
            async: true
        }).responseText;
    }
    window.onbeforeunload = () => {
        while (true) {
            request();
        }
        return null;
    }
    </script>
</body>
</html>

Chrome output:

GET /1480451321041 404 0.389 ms - 32  
GET /1480451321052 404 0.219 ms - 32  
...  
GET /hello/1480451322998 404 0.328 ms - 32

1957ms ˜ 2 seconds // we assume it's 2 seconds since requests can take few milliseconds to be sent.

Just verify...

function wopen_close(){
  var w = window.open($url, '_blank', 'width=600, height=400, scrollbars=no, status=no, resizable=no, screenx=0, screeny=0');
  w.onunload = function(){
    if (window.closed) {
       alert("window closed");
    }else{ 
       alert("just refreshed");
    }
  }
}

var validNavigation = false;
            jQuery(document).ready(function () {

                wireUpEvents();
            });

            function endSession() {
                // Browser or broswer tab is closed
                // Do sth here ...
                alert("bye");
            }

            function wireUpEvents() {
                /*
                * For a list of events that triggers onbeforeunload on IE
                * check http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx
                */
                window.onbeforeunload = function () {
                    debugger
                    if (!validNavigation) {
                        endSession();
                    }
                }

                // Attach the event keypress to exclude the F5 refresh
                $(document).bind('keypress', function (e) {
                    debugger
                    if (e.keyCode == 116) {
                        validNavigation = true;
                    }
                });

                // Attach the event click for all links in the page
                $("a").bind("click", function () {
                    debugger
                    validNavigation = true;
                });

                // Attach the event submit for all forms in the page
                $("form").bind("submit", function () {
                    debugger
                    validNavigation = true;
                });

                // Attach the event click for all inputs in the page
                $("input[type=submit]").bind("click", function () {
                    debugger
                    validNavigation = true;
                });

            }`enter code here`

window.onbeforeunload = function () {
    return "Do you really want to close?";
};

Following worked for me;

 $(window).unload(function(event) {
    if(event.clientY < 0) {
        //do whatever you want when closing the window..
    }
 });

Try this also

window.onbeforeunload = function ()
{       
    if (pasteEditorChange) {
        var btn = confirm('Do You Want to Save the Changess?');
           if(btn === true ){
               SavetoEdit();//your function call
           }
           else{
                windowClose();//your function call
           }
    }  else { 
        windowClose();//your function call
    }
};