onload Event

Event Object Reference Event Object


Execute a JavaScript immediately after a page has been loaded:

<body onload="myFunction()">

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More "Try it Yourself" examples below.

Definition and Usage

The onload event occurs when an object has been loaded.

onload is most often used within the <body> element to execute a script once a web page has completely loaded all content (including images, script files, CSS files, etc.).

The onload event can be used to check the visitor's browser type and browser version, and load the proper version of the web page based on the information.

The onload event can also be used to deal with cookies (see "More Examples" below).

Browser Support

onload Yes Yes Yes Yes Yes



<element onload="myScript">Try it

In JavaScript:

object.onload=function(){myScript};Try it

In JavaScript, using the addEventListener() method:

object.addEventListener("load", myScript);Try it

Note: The addEventListener() method is not supported in Internet Explorer 8 and earlier versions.

Technical Details

Bubbles: No
Cancelable: No
Event type: UIEvent if generated from a user interface, Event otherwise.
Supported HTML tags: <body>, <frame>, <iframe>, <img>, <input type="image">, <link>, <script>, <style>
DOM Version: Level 2 Events


More Examples


Using onload on an <img> element. Alert "Image is loaded" immediately after an image has been loaded:

<img src="w3javascript.gif" onload="loadImage()" width="100" height="132">

function loadImage() {
    alert("Image is loaded");

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Using the onload event to deal with cookies:

<body onload="checkCookies()">

function checkCookies() {
    var text = "";

    if (navigator.cookieEnabled == true) {
       text = "Cookies are enabled.";
    } else {
        text = "Cookies are not enabled.";

    document.getElementById("demo").innerHTML = text;

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Event Object Reference Event Object


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