

DisplayLink docks and dongles do not allow for DDC control on Macs, only software dimming is available for these connections.These displays are supported with software dimming only. Some displays (notably EIZO) use MCCS over USB or an entirely custom protocol for control.Software-only dimming is still available for these connections.
APPLE SECONDARY MONITOR FULL
Use USB-C instead or get BetterDisplay for full DDC control over HDMI with these Macs as well for free.
APPLE SECONDARY MONITOR PRO

Notable exceptions for hardware control compatibility:

for customization options (enable Show advanced settings for even more options). Use your keyboard or the sliders in the app menu (a brightness symbol in the macOS menubar as shown on the screenshot above) to control your displays.Add the app to Accessibility under System Preferences » Privacy & Security » Privacy as prompted (this is required only if you wish to use the native Apple keyboard brightness and media keys - if this is not the case, you can safely skip this step).Copy the MonitorControl app file from the.One of the best app of its kind, completely FREE ( donations welcome) with the source code transparently available!.Simple, unobtrusive UI to blend in to the general aesthetics of macOS.Dozens of customization options to tweak the inner workings of the app to suit your hardware and needs (don't forget to enable Show advanced settings in app Preferences).Support for custom keyboard shortcuts as well as standard brightness and media keys on Apple keyboards.Sync up all your displays using a single slider or keyboard shortcuts.Synchronize brightness from built-in and Apple screens - replicate Ambient light sensor and touch bar induced changes to a non-Apple external display!.Seamlessly combined hardware and software dimming extends dimming beyond the minimum brightness available on your display.

Supports smooth brightness transitions.Supports multiple protocols to adjust brightness: DDC for external displays (brightness, contrast, volume), native Apple protocol for Apple and built-in displays, Gamma table control for software dimming, shade control for AirPlay, Sidecar and Display Link devices and other virtual screens.Shows native OSD for brightness and volume.Control your display's brightness, volume and contrast!.
APPLE SECONDARY MONITOR INSTALL
Brew install MonitorControl Major features
