Ambient Light Events

Deprecated

This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

Warning

Ambient Light Events not supported by any current major browser, and should not be used.

The ambient light events are a handy way to make a web page or an application aware of any change in the light intensity. It allows them to react to such a change, for example by changing the color contrast of the User Interface (UI) or by changing the exposure necessary to take a picture.

Note

This API is not available in Web Workers (it is not exposed in the worker global context).

Light Events

When the light sensor of a device detects a change in the light level, it notifies the browser of that change. When the browser gets such a notification, it fires a DeviceLightEvent event that provides information about the exact light intensity (in lux units).

This event can be captured at the window object level by using the addEventListener method (using the devicelight event name) or by attaching an event handler to the window.ondevicelight property.

Once captured, the event object gives access to the light intensity expressed in lux through the DeviceLightEvent.value property.

Example

if ('ondevicelight' in window) {
  window.addEventListener('devicelight', function(event) {
    var body = document.querySelector('body');
    if (event.value < 50) {
      body.classList.add('darklight');
      body.classList.remove('brightlight');
    } else {
      body.classList.add('brightlight');
      body.classList.remove('darklight');
    }
  });
} else {
  console.log('devicelight event not supported');
}

Specifications

Specification Status Comment
Ambient Light Sensor
The definition of 'Ambient Light Events' in that specification.
Candidate Recommendation Initial definition

Browser compatibility

BCD tables only load in the browser

See also