MonitorControl — Control External Display Brightness and Volume on macOS

Introduction

MonitorControl is a macOS menu bar app that lets you adjust brightness, contrast, and volume on external displays. It communicates with monitors over DDC/CI, the same protocol your monitor's physical buttons use, so changes are applied at the hardware level.

What MonitorControl Does

• Adjusts brightness of external monitors from the macOS menu bar or keyboard
• Controls contrast and volume on supported DDC/CI displays
• Maps native Apple keyboard brightness keys to external monitors
• Supports multiple monitors with independent per-display controls
• Syncs brightness across displays for a uniform experience

Architecture Overview

MonitorControl is a native Swift application that sends DDC/CI commands to external monitors through the I2C interface exposed by macOS display drivers. It hooks into the system media key handler so the standard brightness and volume keys work with third-party monitors just like the built-in display.

Self-Hosting & Configuration

• Install via Homebrew: brew install --cask monitorcontrol
• Also available as a direct download from GitHub Releases
• Requires macOS 11 Big Sur or later
• Grant Accessibility permissions in System Preferences for keyboard shortcut support
• Disable the built-in display brightness OSD if you experience conflicts

Key Features

• Hardware-level brightness control using DDC/CI protocol
• Apple keyboard brightness and volume key integration
• Smooth brightness transitions that mimic the built-in display behavior
• Menu bar slider for quick manual adjustments
• Multi-monitor support with individual or linked brightness curves

Comparison with Similar Tools

• Lunar — offers ambient light sensor integration and advanced scheduling; MonitorControl is free and simpler
• BetterDisplay — provides virtual display features and resolution management; MonitorControl focuses on brightness and volume
• NativeDisplayBrightness — lighter alternative with fewer features; MonitorControl adds contrast, volume, and key mapping
• Display Menu — changes resolution only; MonitorControl targets brightness and DDC/CI controls

FAQ

Q: Does MonitorControl work with all external monitors? A: It works with monitors that support the DDC/CI protocol. Most modern monitors over DisplayPort, HDMI, or USB-C are compatible.

Q: Can I control brightness with keyboard shortcuts? A: Yes. MonitorControl can intercept the standard macOS brightness keys and apply them to external displays.

Q: Is it free and open source? A: Yes. MonitorControl is MIT-licensed and fully open source.

Q: Does it work on Apple Silicon Macs? A: Yes. It runs natively on both Apple Silicon and Intel Macs.

Sources

• https://github.com/MonitorControl/MonitorControl
• https://monitorcontrol.app/