Where is hardware contrast, and how can I change it from Shortcuts?

Look under App Menu > [display] > Device Control for hardware contrast. To change it from Shortcuts while keeping BetterDisplay's managed value in sync, use Image Adjustment with Contrast (Hardware) instead of a raw Send DDC command action.

The display must support hardware contrast through an available controller, and the control must be enabled. For DDC, check Settings > Displays > [display] > Device Control > DDC Control > Configure Controls…. A working brightness command does not by itself establish contrast support.

To show the contrast slider directly in the main display menu, open Settings > Menu > Customize App Menu Contents… and set Contrast to Visible. This changes placement. It does not add hardware support. See Device Control for the remaining hardware adjustments.

In macOS Shortcuts:

  1. Add BetterDisplay's Image Adjustment action.
  2. Select the intended display and choose Contrast (Hardware) as the feature.
  3. Set the desired value. The action maps its percentage to the control's configured minimum and maximum, so the result need not equal the raw number in the monitor's menu.

Send DDC command writes directly to the monitor. It can change the monitor's contrast without changing BetterDisplay's managed slider value. Use it when you deliberately need a raw command. Use the managed feature for ordinary contrast automation. Reading the value back also depends on the monitor's readback support.

Hardware contrast is different from a software image adjustment. See macOS Shortcuts, DDC configuration and monitor versus app percentages for those distinctions and value ranges.

For keyboard access to the main contrast adjustment, assign Increase contrast and Decrease contrast under Settings > Keyboard > Keyboard Shortcuts…. These actions use the preferred contrast controller, which can be software-based. To target hardware contrast specifically, assign a macOS Shortcut using Image Adjustment > Contrast (Hardware). Ordinary F1/F2 shortcuts are separate from the keyboard’s special brightness-key events. Depending on your function-key settings, you may need to hold Fn to send F1/F2.

If you deliberately want DDC brightness commands to adjust hardware contrast instead, open the brightness feature in DDC Control > Configure Controls… and override DDC control code(s) (comma delimited hex values) with 12, the standard contrast code, instead of brightness code 10.

This remaps that DDC brightness control wherever it is used, including its slider. It is not a modifier-key-only contrast shortcut. Record the original setting so you can restore it, and use this only when the monitor supports the contrast command. First check whether an HDR or monitor preset is intentionally locking hardware brightness.