Lumen is a menu bar application for macOS that magically sets the screen brightness based on your screen contents.

You control Lumen simply by using your brightness keys - it'll automatically learn your preferences.

Lumen will automatically brighten the screen when you're looking at a dark window (for example, a full-screen terminal) and it'll automatically darken the screen when you're looking at a bright window (for example, a web browser). This makes for a much more pleasant experience, especially at night.

Without Lumen, web pages are too bright, and the terminal is too dark to read. With Lumen, it's perfect.

The easiest way to install Lumen is to use Homebrew Cask:

brew cask install lumen

Cask makes it easy to manage updates too.

If you prefer, you can manually install the binary. You can find pre-built binaries here.

As of now, releases are not signed with a developer key. To open unsigned applications, use this method.

You can also download and compile the code yourself, if you feel like it.

Note: Lumen isn't supposed to work with auto brightness enabled, so be sure to disable the "automatically adjust brightness as ambient light changes" feature in System Preferences.

Feature requests, bug reports, and pull requests are all appreciated.

• bencevans/lumenaire - a cross platform implementation of Lumen written in Node.js
• meh/dux - a Linux implementation of Lumen (with some extra features) written in Rust
• autolume/autolux - a Linux implementation of Lumen written in Python
• AlaaAlShammaa/Luminance - a Windows implementation of Lumen written in Java

Note: I haven't personally audited the code from these projects.

Copyright (c) 2015-2016 Anish Athalye. Released under GPLv3. See LICENSE.txt for details.