This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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.

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.

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.
Working Draft Initial definition

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
DeviceLightEvent No support 22.0 (22.0)[1][2] No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
DeviceLightEvent No support support 15.0 (15.0)[1][2] No support No support No support

[1] The devicelight event is implemented and preference enabled by default in Firefox Mobile for Android (15.0) and in Firefox OS (B2G). Starting with Gecko 22.0 (Firefox 22.0 / Thunderbird 22.0 / SeaMonkey 2.19) a desktop implementation for Mac OS X is also available. Support for Windows 7 is in progress (see bug 754199).

[2] This event has been disabled by default in Firefox 60, behind the device.sensors.ambientLight.enabled preference (bug 1359076).

See also

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Last updated by: RockoDev,