popstate

The popstate event is fired when the active history entry changes. If the history entry being activated was created by a call to history.pushState() or was affected by a call to history.replaceState(), the popstate event's state property contains a copy of the history entry's state object.

Note that just calling history.pushState() or history.replaceState() won't trigger a popstate event. The popstate event will been triggered by doing a browser action such as a click on the back or forward button (or calling history.back() or history.forward() in JavaScript).

Browsers tend to handle the popstate event differently on page load. Chrome (prior to v34) and Safari always emit a popstate event on page load, but Firefox doesn't.

General info

Specification

HTML5

Interface

PopStateEvent

Bubbles

Yes

Cancelable

No

Target

defaultView

Default Action

None

Properties

Browser compatibility

[1] The implementation has limited support.

[2] The implementation in Android 2.2 and 2.3 was buggy.

[3] IE & Edge do not fire the popstate event when the URL's hash value changes, see the bug report.

Example

A page at https://example.com/example.html running the following code will generate logs as indicated:

window.onpopstate = function(event) {
  console.log("location: " + document.location + ", state: " + JSON.stringify(event.state));
};
history.pushState({page: 1}, "title 1", "?page=1");
history.pushState({page: 2}, "title 2", "?page=2");
history.replaceState({page: 3}, "title 3", "?page=3");
history.back(); // Logs "location: https://example.com/example.html?page=1, state: {"page":1}"
history.back(); // Logs "location: https://example.com/example.html, state: null
history.go(2);  // Logs "location: https://example.com/example.html?page=3, state: {"page":3}

Note that even though the original history entry (for https://example.com/example.html) has no state object associated with it, a popstate event is still fired when we activate that entry after the second call to history.back().

Related Events

• hashchange

See Also

• Manipulating the browser history (the History API)