Products

Monitor Keys

A free menu bar app for macOS that makes the volume and brightness keys work for external monitors, and adds volume and brightness sliders to the menu bar.

Download for Mac

Free.

Requires macOS 15 or later and a Mac with Apple silicon.

By using Monitor Keys, you agree to our Terms of Service and Privacy Policy.

Volume

When sound plays through a monitor over DisplayPort, HDMI or USB‑C, macOS has no volume control for it and the volume keys do nothing. Monitor Keys only acts on outputs like that. The built-in speakers, AirPods and other outputs with their own volume control keep the normal keys.

To set the level, it captures the audio going to the monitor with a Core Audio process tap and plays it back at the level you set, in 16 steps, with mute. No audio driver is installed. The level is remembered for each output.

At full volume there is nothing to turn down, so Monitor Keys captures nothing. Below full, while it captures, macOS shows a purple dot in the menu bar and lists Monitor Keys under System Audio Recording in Control Center. macOS does this for every app that captures system audio; the sound is played straight back and never kept.

Set the monitor’s own volume once to the loudest level you want. The keys turn it down from there; they cannot make it louder than that.

If Monitor Keys quits, the monitor plays at its own volume again.

Brightness

The brightness keys change the brightness of the display under the pointer, in 16 steps. Monitor Keys sends the value to the monitor over DDC/CI, the control channel in the display cable, so the monitor’s own backlight changes.

Your Mac’s built-in display is left to macOS.

The current brightness is read from the monitor when it is connected, when the Mac wakes and when the display setup changes.

Menu

The menu bar icon opens a volume slider (only while Monitor Keys controls the output), a brightness slider for each external display, Start at Login, Check for Updates…, the version number and Quit Monitor Keys. The keys and the sliders show the standard macOS pop-up and stay in step with each other.

Works with

  • Apple silicon Macs (M1 and later) on macOS 15 Sequoia or later
  • Monitors connected over USB‑C, Thunderbolt, DisplayPort or HDMI
  • Monitor speakers, and headphones plugged into the monitor
  • Brightness on monitors with DDC/CI, which most have. On some it must be switched on in the monitor’s own menu
  • Apple keyboards and other keyboards with volume and brightness keys

Does not work with

  • Intel Macs, and macOS 14 or earlier
  • Brightness through most docks, hubs and USB display adapters, which do not pass the monitor’s controls through
  • Brightness through the built-in HDMI port on some Mac models
  • Brightness on monitors without DDC/CI, and on most TVs
  • Wireless displays such as AirPlay and Sidecar

Install

Open the downloaded disk image and drag Monitor Keys to Applications, then open it from there. It runs in the menu bar only, with no Dock icon or window.

The app is signed with a Developer ID and notarized by Apple.

Permissions

Accessibility

To receive the volume and brightness key presses. All other keys pass through untouched.

Allow it in System Settings > Privacy & Security > Accessibility.

System Audio Recording

To capture the sound going to the monitor and play it back at your level, only while the level is below full. The audio is processed in memory and never leaves your Mac.

Allow it in System Settings > Privacy & Security > Screen & System Audio Recording, then quit and reopen Monitor Keys.

Privacy

Monitor Keys collects nothing. There is no account, no analytics and no crash reporting.

Its only network traffic is the update check and the download of an update you install. Like any web request, these show the server your IP address and the app and macOS versions.

Read the privacy policy

Updates

Monitor Keys checks for a new version 10 seconds after launch, then every 6 hours, and when you choose Check for Updates… in the menu. Nothing is installed until you confirm it.

Before installing, it checks that the downloaded app is signed by the same developer as the one you have. It then replaces itself and relaunches.

Contact

Questions, problems and ideas: support@flybywire.se