HTML onload Event Attribute
Example
Execute a JavaScript immediately after a page has been loaded:
<body onload="myFunction()">
Try it Yourself »
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 |
Differences Between HTML 4.01 and HTML5
None.
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>
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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>
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Related Pages
HTML DOM reference: onload event
❮ HTML Event Attributes
