Element: requestFullscreen() method
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.
Syntax
js
requestFullscreen()
requestFullscreen(options)
Parameters
options
Optional-
An object that controls the behavior of the transition to fullscreen mode. The available options are:
-
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.
-
Return value
A Promise
which is resolved with a value of undefined
when
the transition to full screen is complete.
Exceptions
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 Permissions Policy configuration or other access control features. - The element and its document are the same node.
- The element is a popover that is already being shown via
HTMLElement.showPopover()
.
Security
Transient user activation is required. The user has to interact with the page or a UI element in order for this feature to work.
Usage notes
Compatible elements
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 theallowfullscreen
attribute applied to it.
Additionally, any set Permissions Policies must allow the use of this feature.
Detecting fullscreen activation
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 examples 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.
Examples
Requesting fullscreen mode
This function toggles the first <video>
element found in the document
into and out of fullscreen mode.
js
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.
Using navigationUI
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.
js
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()
.
Specifications
Specification |
---|
Fullscreen API Standard # ref-for-dom-element-requestfullscreen① |
Browser compatibility
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