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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.


screenBrightness = window.screen.mozBrightness

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support ? 12.0 (12.0) ? ? ?
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? ? 12.0 (12.0) ? ? ?

Geck0-specific notes

In order to use screen.mozBrightness you have to set the preference "dom.screenBrightnessProperty.enabled" to true in about:config.


Not part of specification.

Document Tags and Contributors

Last updated by: teoli,