Using full-screen mode

This is an experimental feature
Because this feature is still in development in some browsers, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental feature is subject to change in future version of browsers as the spec changes.

The full-screen API provides an easy way for web content to be presented using the user's entire screen. This article provides information about using this API.

Note: This API is early in the standardization process. Although both Gecko and Google Chrome have implementations, they are not currently mutually-compatible, and neither implements the current draft of the specification. For that reason, at least in Firefox, it isn't enabled by default in Firefox 9, but is in Firefox 10. Because the specification is currently an extremely early draft, this documentation is subject to be entirely wrong, and is very preliminary. Once the specification has settled down a bit, the documentation will be cleaned up to be more browser-agnostic.

The API lets you easily direct the browser to make an element and its children, if any, occupy the full screen, eliminating all browser user interface and other applications from the screen for the duration.

Activating full-screen mode

Given an element that you'd like to present in full-screen mode (such as a <video> , for example), you can present it in full-screen mode by simply calling its requestFullScreen() method; this method is implemented in Gecko as element.mozRequestFullScreen() and in WebKit as element.webkitRequestFullScreen().

Let's consider this <video> element:

<video controls id="myvideo">
  <source src="somevideo.webm"></source>
  <source src="somevideo.mp4"></source>

We can put that video into full-screen mode with script like this:

var elem = document.getElementById("myvideo");
if (elem.requestFullScreen) {
} else if (elem.mozRequestFullScreen) {
} else if (elem.webkitRequestFullScreen) {

Presentation differences

It's worth noting a key difference here between the Gecko and WebKit implementations at this time: Gecko automatically adds CSS rules to the element to stretch it to fill the screen: "width: 100%; height: 100%". WebKit doesn't do this; instead, it centers the full-screen element at the same size in a screen that's othewise black. To get the same full-screen behavior in WebKit, you need to add your own "width: 100%; height: 100%;" CSS rules to the element yourself:

:-webkit-full-screen #myvideo {
  width: 100%;
  height: 100%;

On the other hand, if you're trying to emulate WebKit's behavior on Gecko, you need to place the element you want to present inside another element, which you'll make full-screen instead, and use CSS rules to adjust the inner element to match the appearance you want.


When full-screen mode is successfully engaged, the document which contains the full-screen element receives a mozfullscreenchange event. When full-screen mode is exited, the document again receives a  mozfullscreenchange event. Note that the mozfullscreenchange event doesn't provide any information itself as to whether the document is entering or exiting full-screen mode, but if the document has a non null mozFullScreenElement , you know you're in full-screen mode.

When a full-screen request fails

It's not guaranteed that you'll be able to switch into full-screen mode. For example, <iframe> elements have the mozallowfullscreen attribute ( webkitallowfullscreen , et c) in order to opt-in to allowing their content to be displayed in full-screen mode. In addition, certain kinds of content, such as windowed plug-ins, cannot be presented in full-screen mode. Attempting to put an element which can't be displayed in full-screen mode (or the parent or descendant of such an element) won't work. Instead, the element which requested full-screen will receive a mozfullscreenerror event.

Getting out of full screen mode

The user always has the ability to exit full-screen mode of their own accord; see Things your users want to know. You can also do so programmatically by calling the cancelFullScreen() method; this is implemented in Gecko as mozCancelFullScreen() and WebKit as webkitCancelFullScreen().

Other information

The document provides some additional information that can be useful when developing full-screen web applications:

The fullScreen attribute tells you if the document is currently displaying an element in full-screen mode.
The fullScreenElement attribute tells you the element that's currently being displayed full-screen. If this is non-null, the document is in full-screen mode. If this is null, the document is not in full-screen mode.
The fullScreenEnabled attribute tells you whether or not the document is currently in a state that would allow full-screen mode to be requested.

Things your users want to know

You'll want to be sure to let your users know that they can press the ESC key (or F11) to exit full-screen mode.

Also, any alphanumeric keyboard input while in full-screen mode causes a warning message to appear; this is done to help guard against phishing attacks. The following keys are the only ones that don't cause this warning message to appear:

  • left arrow
  • right arrow
  • up arrow
  • down arrow
  • space
  • shift
  • control
  • alt
  • page up
  • page down
  • home
  • end
  • tab
  • meta

In addition, navigating to another page, changing tabs, or switching to another application (using, for example, Alt-Tab) while in full-screen mode exits full-screen mode as well.


In this example, a video is presented in a web page. Pressing the Return or Enter key lets the user toggle between windowed and full-screen presentation of the video.

View the live example

Watching for the Enter key

When the page is loaded, this code is run to set up an event listener to watch for the 'enter' key.

document.addEventListener("keydown", function(e) {
  if (e.keyCode == 13) {
}, false);

Toggling full screen mode

This code is called when the user hits the Enter key, as seen above.

function toggleFullScreen() {
  if ((document.fullScreenElement && document.fullScreenElement !== null) ||    // alternative standard method
      (!document.mozFullScreen && !document.webkitIsFullScreen)) {               // current working methods
    if (document.documentElement.requestFullScreen) {
    } else if (document.documentElement.mozRequestFullScreen) {
    } else if (document.documentElement.webkitRequestFullScreen) {
  } else {
    if (document.cancelFullScreen) {
    } else if (document.mozCancelFullScreen) {
    } else if (document.webkitCancelFullScreen) {

This starts by looking at the value of the fullScreen attribute on the document (checking it prefixed with both -moz- and -webkit-). If it's false, the document is currently in windowed mode, so we need to switch to full-screen mode. The spec draft has a different  fullScreenElement method to check whether or not an element is in full-screen mode, if it's  null then we are in windowed mode. Both gecko and webkit have implemented a the non-standard  fullScreen  method so far. Switching to full-screen mode is done by calling either element.mozRequestFullScreen() or webkitRequestFullScreen(), depending on which is available.

If full screen mode is already active, we call document.mozCancelFullScreen() or webkitCancelFullScreen(), again depending on which browser is in use.

Browser compatibility

Although both Gecko and WebKit implement a draft of this API, there are some subtle differences. This document doesn't necessarily try to call them all into focus. The article will be revised as the spec and implementations fall closer into alignment with one another.

  • Desktop
  • Mobile

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 15  -webkit 9.0 (9.0) -moz ? ? ?
fullScreenEnabled 20 -webkit 10.0 (10.0) -moz ? ? ?
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? 9.0 (9.0) -moz ? ? ?
fullScreenEnabled ? 10.0 (10.0) moz ? ? ?

Gecko notes

Although this API was introduced in Gecko 9.0 (Firefox 9.0 / Thunderbird 9.0 / SeaMonkey 2.6) , it's not enabled by default in that release. To enable it, set the full-screen-api.enabled preference to true. The API is enabled by default in Gecko 10.0 (Firefox 10.0 / Thunderbird 10.0) .


Fullscreen API

Non-standard methods

These are some of the methods that browsers implemented before the standard was drafted. Having the standard methods described above it's better to avoid using the following ones:

  • window.fullScreen (Firefox)
  • HTMLMediaElement.webkitDisplayingFullscreen
  • HTMLMediaElement.webkitEnterFullscreen
  • HTMLMediaElement.webkitExitFullscreen
  • HTMLMediaElement.webkitSupportsFullscreen

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