Adjust Brightness on External Displays in macOS 13

macOS 13 Ventura does not natively support software brightness control or keyboard shortcuts for most third-party, non-Apple external monitors. Because macOS disables the native brightness slider for displays connected via standard HDMI or DisplayPort connections, users must rely on external hardware controls or lightweight third-party utilities that utilize the DDC/CI protocol. This guide covers the most efficient methods to regain control over your external monitor's brightness directly from your Mac.

Third-party utilities communicate directly with your monitor using DDC/CI (Display Data Channel/Command Interface), allowing you to adjust hardware brightness using your Mac keyboard keys (F1 and F2) or the menu bar.

Option A: MonitorControl

MonitorControl is a free, open-source application designed specifically to control external display brightness and volume.

  1. Download MonitorControl from its official GitHub repository or install it via Homebrew (brew install --cask monitorcontrol).
  2. Open the downloaded file and move the application to your Applications folder.
  3. Launch the app. When prompted, grant the app Accessibility permissions in System Settings > Privacy & Security > Accessibility.
  4. Once running, an icon will appear in your menu bar. You can now use the native brightness keys on your Mac keyboard or click the menu bar slider to adjust brightness.

Option B: BetterDisplay

BetterDisplay is a comprehensive display management tool that supports brightness control, software dimming, and custom resolution scaling.

  1. Download and install BetterDisplay.
  2. Open the app and grant the necessary permissions under System Settings > Privacy & Security.
  3. Enable DDC control in the app settings to control the screen hardware directly. If your display or connection does not support DDC (common with certain HDMI adapters), enable "Software Dimming" to lower the screen brightness at the GPU level.

Method 2: Adjust via the Monitor’s Built-in Controls

If software utilities cannot communicate with your display due to adapter limitations, you must use the monitor's built-in On-Screen Display (OSD):

  1. Locate the physical buttons or directional joystick on the bottom or back of your monitor.
  2. Press the menu button to open the monitor’s built-in OSD menu.
  3. Navigate to Picture, Color, or Display Settings.
  4. Select Brightness and adjust the level using the physical navigation buttons.

Method 3: Check Native macOS Display Settings

Some certified Thunderbolt displays allow native control inside macOS 13:

  1. Click the Apple menu in the top-left corner and select System Settings.
  2. Click Displays in the sidebar.
  3. Click your external display at the top of the window.
  4. If your monitor supports native communication, a Brightness slider will be visible beneath the display arrangement. If no slider appears, your monitor requires Method 1 or Method 2.