Web/API/GlobalEventHandlers/onload

The onload property of the GlobalEventHandlers mixin is an EventHandler that processes load events on a Window, XMLHttpRequest, <img> element, etc.

The load event fires when a given resource has loaded.

Syntax

target.onload = functionRef;

Value

functionRef is the handler function to be called when the window’s load event fires.

Examples

window.onload = function() {
  init();
  doSomethingElse();
};

<!doctype html>
<html>
  <head>
    <title>onload test</title>
    // ES5
    <script>
      function load() {
        console.log("load event detected!");
      }
      window.onload = load;
    </script>
    // ES2015 
    <script>
      const load = () => {
        console.log("load event detected!");
      } 
      window.onload = load; 
    </script>
  </head>
  <body>
    <p>The load event fires when the document has finished loading!</p>
  </body>
</html>

Notes

The load event fires at the end of the document loading process. At this point, all of the objects in the document are in the DOM, and all the images, scripts, links and sub-frames have finished loading.

There are also DOM Events like DOMContentLoaded and DOMFrameContentLoaded (which can be handled using EventTarget.addEventListener()) which are fired after the DOM for the page has been constructed, but do not wait for other resources to finish loading.

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'onload' in that specification.	Living Standard	Initial definition

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`onload`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 9	Opera Full support 9	Safari Full support 3	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0

Legend

Full support: Full support