HTML onload Event Attribute

Example

Execute a JavaScript immediately after a page has been loaded:

More "Try it Yourself" examples below.

Definition and Usage

The onload attribute fires 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.). However, it can be used on other elements as well (see "Supported HTML tags" below).

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

Browser Support

Event Attribute
onload	Yes	Yes	Yes	Yes	Yes

Syntax

<element onload="script">

Attribute Values

Value	Description
script	The script to be run on onload

Technical Details

Supported HTML tags:	<body>, <frame>, <frameset>, <iframe>, <img>, <input type="image">, <link>, <script> and <style>

More Examples

Example

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

<img src="w3html.gif" onload="loadImage()" width="100" height="132">

<script>
function loadImage() {
alert("Image is loaded");
}
</script>

Try it Yourself »

Example

Using the onload event to deal with cookies (using "advanced" javascript):

<body onload="checkCookies()">

<p id="demo"></p>

<script>
function checkCookies() {
    var text = "";
    if (navigator.cookieEnabled == true) {
        text = "Cookies are enabled.";
    } else {
        text = "Cookies are not enabled.";
    }
    document.getElementById("demo").innerHTML = text;
}
</script>

Try it Yourself »

HTML DOM reference: onload event

❮ HTML Event Attributes