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Is it possible to dim the screen from Terminal, in a Mac with OS X Lion? Is there any command to do control brightness and volume?

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up vote 13 down vote accepted

You can do it via an Applescript and run it as such:


tell application "System Events"
        key code 107
    end tell


tell application "System Events"
        key code 113
    end tell

You can save these as .script files and then run them from the CLI like this:

osascript ~/Path/to/File

You can also do it this way, but that requires more setup.

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You can install this command line tool from The install is pretty easy if you have homebrew:

brew install brightness

And usage is straightforward:

  • Set 100% brightness: brightness 1
  • Set 50% brightness: brightness 0.5

Unfortunately it doesn't work for external monitors. See Does Apple support DDC/CI for 3rd party displays via Apple's Thunderbolt to DVI adapter for background on why.

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For me, these instructions installed a command called brightness, not screenbrightness. Otherwise, this worked as described. Thanks! – octern Oct 10 '15 at 12:42


I've created a node module for this that supports setting the brightness using the CLI. See

npm install --global brightness-cli

And then simply just run brightness from your command line.

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Doesn't work for me: $ brightness 100 /usr/local/lib/node_modules/brightness-cli/cli.js:3 const brightness = require('brightness'); ^^^^^ SyntaxError: Use of const in strict mode. at Module._compile (module.js:439:25) at Object.Module._extensions..js (module.js:474:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:312:12) at Function.Module.runMain (module.js:497:10) at startup (node.js:119:16) at node.js:902:3 – Kibber Jun 23 at 21:29

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