Change the URL in the browser without loading the new page using JavaScript

Question

If you want it to work in browsers that don't support history.pushState and history.popState yet, the "old" way is to set the fragment identifier, which won't cause a page reload.

The basic idea is to set the window.location.hash property to a value that contains whatever state information you need, then either use the window.onhashchange event, or for older browsers that don't support onhashchange (IE < 8, Firefox < 3.6), periodically check to see if the hash has changed (using setInterval for example) and update the page. You will also need to check the hash value on page load to set up the initial content.

If you're using jQuery there's a hashchange plugin that will use whichever method the browser supports. I'm sure there are plugins for other libraries as well.

One thing to be careful of is colliding with ids on the page, because the browser will scroll to any element with a matching id.

With HTML 5, use the history.pushState function. As an example:

<script type="text/javascript">
var stateObj = { foo: "bar" };
function change_my_url()
{
   history.pushState(stateObj, "page 2", "bar.html");
}
var link = document.getElementById('click');
link.addEventListener('click', change_my_url, false);
</script>

and a href:

<a href="#" id='click'>Click to change url to bar.html</a>

---

If you want to change the URL without adding an entry to the back button list, use history.replaceState instead.

window.location.href contains the current URL. You can read from it, you can append to it, and you can replace it, which may cause a page reload.

If, as it sounds like, you want to record javascript state in the URL so it can be bookmarked, without reloading the page, append it to the current URL after a # and have a piece of javascript triggered by the onload event parse the current URL to see if it contains saved state.

If you use a ? instead of a #, you will force a reload of the page, but since you will parse the saved state on load this may not actually be a problem; and this will make the forward and back buttons work correctly as well.

I would strongly suspect this is not possible, because it would be an incredible security problem if it were. For example, I could make a page which looked like a bank login page, and make the URL in the address bar look just like the real bank!

Perhaps if you explain why you want to do this, folks might be able to suggest alternative approaches...

[Edit in 2011: Since I wrote this answer in 2008, more info has come to light regarding an HTML5 technique that allows the URL to be modified as long as it is from the same origin]

jQuery has a great plugin for changing browsers' URL, called jQuery-pusher.

JavaScript pushState and jQuery could be used together, like:

history.pushState(null, null, $(this).attr('href'));

Example:

$('a').click(function (event) {

  // Prevent default click action
  event.preventDefault();     

  // Detect if pushState is available
  if(history.pushState) {
    history.pushState(null, null, $(this).attr('href'));
  }
  return false;
});

Using only JavaScript history.pushState(), which changes the referrer, that gets used in the HTTP header for XMLHttpRequest objects created after you change the state.

Example:

window.history.pushState("object", "Your New Title", "/new-url");

The pushState() method:

pushState() takes three parameters: a state object, a title (which is currently ignored), and (optionally) a URL. Let's examine each of these three parameters in more detail:

1. state object — The state object is a JavaScript object which is associated with the new history entry created by pushState(). Whenever the user navigates to the new state, a popstate event is fired, and the state property of the event contains a copy of the history entry's state object.

   The state object can be anything that can be serialized. Because Firefox saves state objects to the user's disk so they can be restored after the user restarts her browser, we impose a size limit of 640k characters on the serialized representation of a state object. If you pass a state object whose serialized representation is larger than this to pushState(), the method will throw an exception. If you need more space than this, you're encouraged to use sessionStorage and/or localStorage.

2. title — Firefox currently ignores this parameter, although it may use it in the future. Passing the empty string here should be safe against future changes to the method. Alternatively, you could pass a short title for the state to which you're moving.

3. URL — The new history entry's URL is given by this parameter. Note that the browser won't attempt to load this URL after a call to pushState(), but it might attempt to load the URL later, for instance after the user restarts her browser. The new URL does not need to be absolute; if it's relative, it's resolved relative to the current URL. The new URL must be of the same origin as the current URL; otherwise, pushState() will throw an exception. This parameter is optional; if it isn't specified, it's set to the document's current URL.

Browser security settings prevent people from modifying the displayed url directly. You could imagine the phishing vulnerabilities that would cause.

Only reliable way to change the url without changing pages is to use an internal link or hash. e.g.: http://site.com/page.html becomes http://site.com/page.html#item1 . This technique is often used in hijax(AJAX + preserve history).

When doing this I'll often just use links for the actions with the hash as the href, then add click events with jquery that use the requested hash to determine and delegate the action.

I hope that sets you on the right path.

There is a Yahoo YUI component (Browser History Manager) which can handle this: http://developer.yahoo.com/yui/history/