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 Standard
The definition of 'onload' in that specification.
Living Standard Initial definition

Browser compatibility

BCD tables only load in the browser

See also