The HashChangeEvent interface represents events that fire when the fragment identifier of the URL has changed.

The fragment identifier is the part of the URL that follows (and includes) the # symbol.


This interface also inherits the properties of its parent, Event.

HashChangeEvent.newURL Read only
The new URL to which the window is navigating.
HashChangeEvent.oldURL Read only
The previous URL from which the window was navigated.


This interface has no methods of its own, but inherits the methods of its parent, Event.


Syntax options for a hash change

You can listen for the hashchange event using any of the following options:

window.onhashchange = funcRef;


<body onhashchange="funcRef();">


window.addEventListener("hashchange", funcRef, false);

Basic example

function locationHashChanged() {
  if (location.hash === '#somecoolfeature') {

window.addEventListener('hashchange', locationHashChanged);


There are several fallback scripts listed on the Modernizr GitHub page. Basically, those scripts check the location.hash at a regular interval. Here is a version that allows only one handler to be bound to the onhashchange property:

;(function(window) {

  // Exit if the browser implements that event
  if ( "onhashchange" in window.document.body ) { return; }

  var location = window.location,
      oldURL = location.href,
      oldHash = location.hash;

  // Check the location hash on a 100ms interval
  setInterval(function() {
    var newURL = location.href,
        newHash = location.hash;

    // If the hash has changed and a handler has been bound...
    if ( newHash != oldHash && typeof window.onhashchange === "function" ) {
      // Execute the handler
        type: "hashchange",
        oldURL: oldURL,
        newURL: newURL

      oldURL = newURL;
      oldHash = newHash;
  }, 100);



Specification Status Comment
HTML Living Standard
The definition of 'HashChangeEvent' in that specification.
Living Standard Initial definition

Browser compatibility

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