WakeLockSentinel

Draft
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Secure context
This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The WakeLockSentinel interface of the Screen Wake Lock API provides a handle to the underlying platform wake lock and can be manually released and reacquired. An Object representing the wake lock is returned via the navigator.wakelock.request() method.

An acquired WakeLockSentinel can be released manually via the release() method, or automatically via the platform wake lock. This can happen if the document becomes inactive or looses visibility, if the device is low on power or the user turns on a power save mode. Releasing all WakeLockSentinel instances of a given wake lock type will cause the underlying platform wake lock to be released.

Properties

This interface provides the following properties.

released Read only
Returns a boolean indicating whether the WakeLockSentinel has been released.
type Read only
Returns a String representation of the currently acquired WakeLockSentinel type.
Return values are:
  • 'screen': A screen wake lock. Prevents devices from dimming or locking the screen.

Event handlers

onrelease
Fired when the release() method is called or the wake lock is released by the user agent.

Methods

release()
Releases the WakeLockSentinel, returning a Promise that is resolved once the sentinel has been successfully released.

Examples

In this example we create an asynchronous function which requests a WakeLockSentinel. Once acquired we listen for the onrelease event which can be used to give appropriate UI feedback. The sentinel can be acquired or released via appropriate interactions.

// create a reference for the wake lock
let wakeLock = null;

// create an async function to request a wake lock
const requestWakeLock = async () => {
  try {
    wakeLock = await navigator.wakeLock.request('screen');

    // listen for our release event
    wakeLock.addEventListener('release', () => {
      // if wake lock is released alter the UI accordingly
    });

  } catch (err) {
    // if wake lock request fails - usually system related, such as battery

  }
}

wakeLockOnButton.addEventListener('click', () => {
  requestWakeLock();
})

wakeLockOffButton.addEventListener('click', () => {
  if (wakeLock !== null) {
    wakeLock.release()
      .then(() => {
        wakeLock = null;
      })
  }
})

Specifications

Specification Status Comment
Screen Wake Lock API
The definition of 'WakeLockSentinel' in that specification.
Editor's Draft Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
WakeLockSentinel
Experimental
Chrome Full support 84Edge Full support 84Firefox No support NoIE No support NoOpera Full support YesSafari No support NoWebView Android Full support 84Chrome Android Full support 84Firefox Android No support NoOpera Android Full support YesSafari iOS No support NoSamsung Internet Android No support No
onrelease
Experimental
Chrome Full support 84Edge Full support 84Firefox No support NoIE No support NoOpera Full support YesSafari No support NoWebView Android Full support 84Chrome Android Full support 84Firefox Android No support NoOpera Android Full support YesSafari iOS No support NoSamsung Internet Android No support No
release
Experimental
Chrome Full support 84Edge Full support 84Firefox No support NoIE No support NoOpera Full support YesSafari No support NoWebView Android Full support 84Chrome Android Full support 84Firefox Android No support NoOpera Android Full support YesSafari iOS No support NoSamsung Internet Android No support No
released
Experimental
Chrome Full support 87Edge Full support 87Firefox No support NoIE No support NoOpera Full support YesSafari No support NoWebView Android Full support 87Chrome Android Full support 87Firefox Android No support NoOpera Android Full support YesSafari iOS No support NoSamsung Internet Android No support No
type
Experimental
Chrome Full support 84Edge Full support 84Firefox No support NoIE No support NoOpera Full support YesSafari No support NoWebView Android Full support 84Chrome Android Full support 84Firefox Android No support NoOpera Android Full support YesSafari iOS No support NoSamsung Internet Android No support No

Legend

Full support  
Full support
No support  
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.