25 December 2018

ddcutil release 0.9.4 fixes a bug that caused the capabilities command to fail, and addresses the failure to build from source for the x32 ABI.

For a complete list of changes and bug fixes, see Release Notes. Prior announcements can be found here.

26 November 2018

ddcutil release 0.9.3 reworks display detection to avoid problems encountered with certain recent displays and laptops. There have been extensive internal changes to allow for future support of user supplied definitions for manufacturer-specific features. The API has also been revised to support user supplied feature definitions (see API Changes in Release 0.9.3).

For a complete list of changes and bug fixes, see Release Notes. Prior announcements can be found here.

ddcui release 0.0.3 reflects changes to the ddcutil API.


ddcutil is a Linux program for managing monitor settings, such as brightness, color levels, and input source. Generally speaking, any settings that can be changed by pressing buttons on the monitor can be modified by ddcutil.

ddcutil primarily uses DDC/CI (Display Data Channel Command Interface) to communicate with monitors implementing MCCS (Monitor Control Command Set) over I2C. Normally, the video driver for the monitor exposes the I2C channel as devices named /dev/i2c-n. Alternatively, there is support for monitors (such as Eizo ColorEdge displays) that implement MCCS using a USB connection. See USB Connected Monitors.

A particular use case for ddcutil, and the one that inspired its development, is as part of color profile management. Monitor calibration is relative to the monitor color settings currently in effect, e.g. red gain. ddcutil allows color related settings to be saved at the time a monitor is calibrated, and then restored when the calibration is applied.


  • ddcutil does not support laptop displays, which are controlled using a special API, not I2C.
  • Nvidia's proprietary video driver may require special configuration. See Special Nvidia Driver Settings.
  • Operation with AMD's proprietary video driver fglrx requires a specially built version of ddcutil. See Building with ADL Support.
  • Reading and writing Table type features is implemented but untested. See Table Features

ddcutil is released under the GNU Public License, V2 (GPLV2). The source is hosted on Github.

General support questions are best directed the to the issue tracker on Github. Use of that forum allows everyone to benefit from individual questions and ideas. For details, see Technical Support.


Using ddcutil:

Installation and Configuration:



Sanford Rockowitz rockowitz@minsoft.com