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DDC monitor controls (brightness) for Mac OSX command line
C Objective-C Makefile Shell
Branch: master
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ddcctl: DDC monitor controls for the OSX command line

Adjust your external monitors' built-in controls from the OSX shell:

  • brightness
  • contrast

And possibly (if your monitor firmware is well implemented):

  • input source
  • built-in speaker volume
  • on/off/standby
  • rgb colors
  • color presets
  • reset


  • install Xcode
  • figure out if your Mac is using an Intel, Nvidia or AMD gpu
  • run make intel or make make nvidia or make amd


Run ddcctl -h for some options. is a script I use to control two PC monitors plugged into my Mac Mini.
You can point Alfred, ControlPlane, or Karabiner at it to quickly switch presets.

Input Sources

When setting input source, refer to the table below to determine which value to use. For example, to set your first display to HDMI: ddcctl -d 1 -i 17

Input Source Value
VGA-1 1
VGA-2 2
DVI-1 3
DVI-2 4
Composite video 1 5
Composite video 2 6
S-Video-1 7
S-Video-2 8
Tuner-1 9
Tuner-2 10
Tuner-3 11
Component video (YPrPb/YCrCb) 1 12
Component video (YPrPb/YCrCb) 2 13
Component video (YPrPb/YCrCb) 3 14
DisplayPort-1 15
DisplayPort-2 16
HDMI-1 17
HDMI-2 18


ddcctl.m sprang from a forum thread on the TonyMac-x86 boards.

DDC.c originated from jontaylor/DDC-CI-Tools-for-OS-X, but was reworked by others on the forums.

A few forks have also backported patches, which is nice 👌.

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