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 and keep BetterDisplay’s slider 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 monitor may support brightness changes without supporting contrast.

To show the contrast slider directly in a display’s main menu block, 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 converts its percentage using the configured minimum and maximum. This percentage may differ from the number in the monitor’s own menu.

Send DDC command writes directly to the monitor. It can change the monitor's contrast without changing BetterDisplay's managed slider value. Use the raw action when you need to send a specific DDC value. For ordinary contrast changes, use Image Adjustment > Contrast (Hardware). 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). To assign F1 or F2, use the keys as ordinary function keys. Depending on your keyboard settings, you may need to hold Fn. Their brightness-key functions are separate.

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 makes the DDC brightness control adjust contrast wherever it is used, including its slider. The change is not limited to one keyboard 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.