brightctrl

Monitor brightness, straight from your terminal.

Adjust the brightness of your external monitors without leaving the keyboard. A single native binary — no ddcutil, no Node.js, no runtime dependencies. Linux talks DDC/CI directly over i2c; Windows uses the Monitor Configuration API.

npx brightctrl

# or grab a binary from the latest release

brightctrl

brightctrl --help

Description

One native binary — no ddcutil, no Node.js, no runtime deps.
DDC/CI straight over i2c on Linux; Monitor Configuration API on Windows.
A TUI when you want one, a CLI when you're scripting.
Name a monitor once, then target it by alias instead of an id.
Sync every monitor at once, or drop to 1% steps.
Config is plain TOML at ~/.config/brightctrl/config.toml.

Commands

brightctrl: open the interactive TUI
brightctrl list: monitors with ids, aliases, brightness
brightctrl get <target>: print brightness (0-100)
brightctrl set <target> <0-100>: set brightness
brightctrl alias <id> <name>: name a monitor
brightctrl alias <id>: remove the alias

# <target> is a monitor number (1), an id (GSM7707), or an alias (left).

# press ? in the TUI

Keys

↑ ↓ / k j: Pick a monitor
← → / h l: Brightness down / up
1 – 9: Select monitor by number
/: Type an exact value (0-100)
p: Precise mode — 1% steps
s: Sync — all monitors at once
m: Set brightness to 0
r: Refresh monitor list
?: Help
q: Quit

Install

npm / npxLinux & Windows, x64

$ npx brightctrl

Arch (AUR)

$ yay -S brightctrl

ScoopWindows

$ scoop install brightctrl

WinGetWindows

$ winget install shahriyardx.brightctrl

Cargofrom source

$ cargo install --git https://github.com/shahriyardx/brightctrl

Linux setup

# DDC/CI needs the i2c module and group access — once.

sudo modprobe i2c-dev
echo i2c-dev | sudo tee /etc/modules-load.d/i2c.conf
sudo usermod -aG i2c $USER   # then log out and back in

# On Windows: nothing to do — just enable DDC/CI in your monitor’s OSD if list comes up empty.

Config

# ~/.config/brightctrl/config.toml
[aliases]
GSM7707 = "left"
27M2N5500 = "main"
LG-HDR-4K = "up"

# Aliases live here. Set them with brightctrl alias — or edit the file.

cat Cargo.toml

Rust · ratatui · clap · ddc · serde · toml — Linux i2c and the Windows Monitor Configuration API, from one source tree. MIT.