Element.requestFullscreen()

The Element.requestFullscreen() method issues an asynchronous request to make the element be displayed in fullscreen mode.

It's not guaranteed that the element will be put into full screen mode. If permission to enter full screen mode is granted, the returned Promise will resolve and the element will receive a fullscreenchange event to let it know that it's now in full screen mode. If permission is denied, the promise is rejected and the element receives a fullscreenerror event instead. If the element has been detached from the original document, then the document receives these events instead.

options Optional

An object that controls the behavior of the transition to fullscreen mode. See below for available options.

navigationUI

Controls whether or not to show navigation UI while the element is in fullscreen mode. The default value is "auto", which indicates that the browser should decide what to do.

• "hide": The browser's navigation interface will be hidden and the entire dimensions of the screen will be allocated to the display of the element.
• "show": The browser will present page navigation controls and possibly other user interface; the dimensions of the element (and the perceived size of the screen) will be clamped to leave room for this user interface.
• "auto": The browser will choose which of the above settings to apply. This is the default value.

A Promise which is resolved with a value of undefined when the transition to full screen is complete.

Rather than throw a traditional exception, the requestFullscreen() procedure announces error conditions by rejecting the Promise it has returned. The rejection handler receives one of the following exception values:

TypeError

The TypeError exception may be delivered in any of the following situations:

• The document containing the element isn't fully active; that is, it's not the current active document.
• The element is not contained by a document.
• The element is not permitted to use the "fullscreen" feature, either because of Feature Policy configuration or other access control features.
• The element and its document are the same node.

An element that you wish to place into fullscreen mode has to meet a small number of simple requirements:

• It must be one of the standard HTML elements or <svg> or <math>.
• It is not a <dialog> element.
• It must either be located within the top-level document or in an <iframe> which has the allowfullscreen attribute applied to it.

Additionally, of course, the Feature Policy "fullscreen" permission must be granted.

You can determine whether or not your attempt to switch to fullscreen mode is successful by using the Promise returned by requestFullscreen(), as seen in the Example below.

To learn when other code has toggled fullscreen mode on and off, you should establish listeners for the fullscreenchange event on the Document. It's also important to listen for fullscreenchange to be aware when, for example, the user manually toggles fullscreen mode, or when the user switches applications, causing your application to temporarily exit fullscreen mode.

This function toggles the first <video> element found in the document into and out of fullscreen mode.

function toggleFullscreen() {
  let elem = document.querySelector("video");

  if (!document.fullscreenElement) {
    elem.requestFullscreen().catch(err => {
      alert(`Error attempting to enable fullscreen mode: ${err.message} (${err.name})`);
    });
  } else {
    document.exitFullscreen();
  }
}

If the document isn't already in fullscreen mode—detected by looking to see if document.fullscreenElement has a value—we call the video's requestFullscreen() method. We don't need to do anything special if successful, but if the request fails, our promise's catch() handler presents an alert with an appropriate error message.

If, on the other hand, fullscreen mode is already in effect, we call document.exitFullscreen() to disable fullscreen mode.

You can see this example in action or view or remix the code on Glitch.

In this example, the entire document is placed into fullscreen mode by calling requestFullscreen() on the document's Document.documentElement, which is the document's root <html> element.

let elem = document.documentElement;

elem.requestFullscreen({ navigationUI: "show" }).then(() => {}).catch(err => {
  alert(`An error occurred while trying to switch into fullscreen mode: ${err.message} (${err.name})`);
});

The promise's resolve handler does nothing, but if the promise is rejected, an error message is displayed by calling alert().

• Fullscreen API
• Document.exitFullscreen()
• Document.fullscreen
• Document.fullscreenElement
• :fullscreen
• allowfullscreen