[jquery] Difference between $(window).load() and $(document).ready() functions

What is the difference between $(window).load(function() {}) and $(document).ready(function() {}) in jQuery?

This question is related to jquery

The answer is


The $(window).load() is NOT available in jQuery 3.0

$( window ).load(function() {
        // Handler for .load() called.
});

To get around it, you can use it as an "Event Handler Attachment"

$( window ).on("load", function() {
        // Handler for .load() called.
});

<html>
<head>
    <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
    <script>
    $( document ).ready(function() {
        alert( "document loaded" );
    });

    $( window ).load(function() {
        alert( "window loaded" );
    });
    </script>
</head>
<body>
    <iframe src="http://stackoverflow.com"></iframe>
</body>
</html>

window.load will be triggered after all the iframe content is loaded


document.ready (jQuery) document.ready will execute right after the HTML document is loaded property, and the DOM is ready.

DOM: The Document Object Model (DOM) is a cross-platform and language-independent convention for representing and interacting with objects in HTML, XHTML and XML documents.

$(document).ready(function()
{
   // executes when HTML-Document is loaded and DOM is ready
   alert("(document).ready was called - document is ready!");
});

window.load (Built-in JavaScript) The window.load however will wait for the page to be fully loaded, this includes inner frames, images etc. * window.load is a built-in JavaScript method, it is known to have some quirks in old browsers (IE6, IE8, old FF and Opera versions) but will generally work in all of them.

window.load can be used in the body's onload event like this (but I would strongly suggest you avoid mixing code like this in the HTML, as it is a source for confusion later on):

$(window).load(function() 
{
   // executes when complete page is fully loaded, including all frames, objects and images
   alert("(window).load was called - window is loaded!");
});

According to DOM Level 2 Events, the load event is supposed to fire on document, not on window. However, load is implemented on window in all browsers for backwards compatibility.


The difference are:

$(document).ready(function() { is jQuery event that is fired when DOM is loaded, so it’s fired when the document structure is ready.

$(window).load() event is fired after whole content is loaded.


I think the $(window).load event is not supported by JQuery 3.x


$(window).load is an event that fires when the DOM and all the content (everything) on the page is fully loaded like CSS, images and frames. One best example is if we want to get the actual image size or to get the details of anything we use it.

$(document).ready() indicates that code in it need to be executed once the DOM got loaded and ready to be manipulated by script. It won't wait for the images to load for executing the jQuery script.

<script type = "text/javascript">
    //$(window).load was deprecated in 1.8, and removed in jquery 3.0
    // $(window).load(function() {
    //     alert("$(window).load fired");
    // });

    $(document).ready(function() {
        alert("$(document).ready fired");
    });
</script>

$(window).load fired after the $(document).ready().

$(window).load was deprecated in 1.8, and removed in jquery 3.0


$(document).ready(function() {
 // executes when HTML-Document is loaded and DOM is ready
 alert("document is ready");
});


$(window).load(function() {
 // executes when complete page is fully loaded, including all frames, objects and images
 alert("window is loaded");
});

From jquery prospective - it's just adding load/onload event to window and document. Check this out:

window.onload vs document.onload


$(document).ready happens when all the elements are present in the DOM, but not necessarily all content.

$(document).ready(function() {
    alert("document is ready");
});

window.onload or $(window).load() happens after all the content resources (images, etc) have been loaded.

$(window).load(function() {
    alert("window is loaded");
});