Free Download Available

Adjust your external display's brightness
just like your MacBook.

A menu bar app that adjusts external display brightness.
Works with Apple keyboard brightness keys 🔅🔆.
On MacBook, it even syncs with auto-brightness.
No more struggling with too-bright or too-dark screens.
And it's free.

free
rune Lux concept visual showing golden displays and brightness adjustment imagery.

Software-Based Brightness Control for External Displays

Adjust external display brightness with the brightness keys 🔅🔆.
On MacBook, auto-brightness sync keeps your displays matched automatically —
an eye-friendly workspace with zero effort.

Adjust External Display Brightness with Software

Uses gamma table adjustment to control your external display's brightness in software. Fine-tune across 64 levels, down to 10% brightness at minimum. Screenshots and screen recordings remain unaffected, so your work captures stay clean.

Auto-Sync with MacBook Display

When your MacBook's display brightness changes, the external stays in sync. Working hand in hand with macOS auto-brightness — when the room gets darker, external displays dim along with it, and brighten again when the lights come back. Even with multiple displays, you get a seamless, unified viewing experience.

Intuitive Keyboard Control

Use your Apple keyboard's brightness keys 🔅🔆 to adjust external displays directly. Hold Shift+Option for fine-grained single-step control. You can also assign custom shortcut keys to suit your workflow.

Adjust from the Menu Bar

Click the sun icon in the menu bar to open a slider for direct adjustment. The current brightness level is shown as a number, so you always know the current adjustment level. No Dock icon means zero clutter.

Screenshots & Screen Recordings Stay Clean

Because rune Lux adjusts brightness via gamma tables, screenshots and screen recordings are completely unaffected. Work on an adjusted screen, and still capture clean images and videos every time.

Adapts to Display Changes Automatically

Plug in an external display and gamma settings are applied instantly. Disconnect it, and monitoring pauses on its own. Whether you're docking, undocking, or toggling power, rune Lux follows along seamlessly.

Dead Simple to Use
Just 3 Steps

rune Lux lives in your menu bar and is ready to go after a one-time permission setup.

Just press the brightness key. Auto-sync with your MacBook display is on from the start.

1. Grant Permission
2. Press Brightness Key
3. Display Adjusts
free

Make Your External Display Easier on the Eyes

Brightness keys 🔅🔆 and auto-sync take display adjustment to the next level.
Free to download and use.

Requires macOS 13.0 or later (Apple Silicon & Intel)