Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
Indicates how bright the screen's backlight is, on a scale from 0 (very dim) to 1 (full brightness); this value is a double-precision float.
You can read and write this attribute even when the screen is disabled, but the backlight is off while the screen is disabled. If you write a value of X into this attribute, the attribute may not have the same value X when you later read it. Most screens don't support as many different brightness levels as there are doubles between 0 and 1. The value's precision might be reduced before storing it.
Syntax
screenBrightness = window.screen.mozBrightness;
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | ? | 12.0 (12.0)[1] | ? | ? | ? |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | ? | ? | 12.0 (12.0)[1] | ? | ? | ? |
[1] In order to use screen.mozBrightness you have to set the preference dom.screenBrightnessProperty.enabled to true in about:config.
Specification
Not part of specification.