ddcutil vs DisplayBuddy

ddcutil is a free Linux program for controlling monitor settings such as brightness, color levels and input source. It communicates with monitors through DDC/CI over I²C and supports monitors implementing MCCS over USB. Commands can find monitors, show capabilities, read or change VCP feature values, and save or restore color-related settings. The companion ddcui provides a Qt graphical interface with Summary, Capabilities and Features views, with the last allowing changes to modifiable values. For profile workflows, dumpvcp saves current settings to a file and loadvcp restores them. Developers can use the C API through libddcutil.so to read and write VCP values and handle profile-related features. The program is released under GNU GPL version 2. Setup requires the Linux kernel i2c-dev module, and non-root users need permissions to run it. It does not support laptop displays, which use a special API rather than I²C, and generally will not run in virtual machines because virtual video drivers do not implement I²C. For MCCS-over-USB table features, support is limited; the capabilities command synthesizes a response.

DisplayBuddy controls supported external monitor settings from a Mac menu bar or Windows taskbar. Depending on the display, it can adjust brightness, contrast, speaker volume, input source, resolution, and rotation. The Mac app uses DDC for hardware control and can use gamma dimming when a monitor does not respond. The maker says it also controls supported LG webOS and Samsung Tizen smart monitors over Wi-Fi. Users can save presets and synchronize brightness across displays. On Mac, presets can be scheduled by sunrise, sunset, time of day, charger state, or connected display; the app also supports Shortcuts, Siri, a command-line interface, and MCP. The Windows app supports Windows 10 and 11, with presets, hotkeys, input switching, and resolution and refresh-rate controls. Personal costs $24.99, paid once for one Mac, Pro costs $29.99, paid once for up to two Macs, and Family costs $49.99, paid once for up to five Macs; each includes lifetime access. There is no free plan, but a 7-day trial is available. Core controls work offline after internet-based license activation.