interface HTMLBodyElement : HTMLElement {
           attribute EventHandler onafterprint;
           attribute EventHandler onbeforeprint;
           attribute EventHandler onbeforeunload;
           attribute EventHandler onblur;
           attribute OnErrorEventHandler onerror;
           attribute EventHandler onfocus;
           attribute EventHandler onhashchange;
           attribute EventHandler onload;
           attribute EventHandler onmessage;
           attribute EventHandler onoffline;
           attribute EventHandler ononline;
           attribute EventHandler onpopstate;
           attribute EventHandler onpagehide;
           attribute EventHandler onpageshow;
           attribute EventHandler onresize;
           attribute EventHandler onscroll;
           attribute EventHandler onstorage;
           attribute EventHandler onunload;
};

The body element represents the main content of the document.

In conforming documents, there is only one body element. The document.body IDL attribute provides scripts with easy access to a document's body element.

The body element exposes as event handler content attributes a number of the event handlers of the Window object. It also mirrors their event handler IDL attributes.

The onblur, onerror, onfocus, onload, and onscroll event handlers of the Window object, exposed on the body element, shadow the generic event handlers with the same names normally supported by HTML elements.

Thus, for example, a bubbling error event dispatched on a child of the body element of a Document would first trigger the onerror event handler content attributes of that element, then that of the root html element, and only then would it trigger the onerror event handler content attribute on the body element. This is because the event would bubble from the target, to the body, to the html, to the Document, to the Window, and the event handler on the body is watching the Window not the body. A regular event listener attached to the body using addEventListener(), however, would be run when the event bubbled through the body and not when it reaches the Window object.

This page updates an indicator to show whether or not the user is online:

<!DOCTYPE HTML>
<html>
 <head>
  <title>Online or offline?</title>
  <script>
   function update(online) {
     document.getElementById('status').textContent =
       online ? 'Online' : 'Offline';
   }
  </script>
 </head>
 <body ononline="update(true)"
       onoffline="update(false)"
       onload="update(navigator.onLine)">
  <p>You are: <span id="status">(Unknown)</span></p>
 </body>
</html>

HTML5

4.4.1 The body element

4.4.1 The `body` element