I work in a dark room a lot, and even the lowest keyboard backlight setting on my MacBook was too bright. I noticed macOS fades the backlight all the way to zero when it turns off, but the lowest level it lets you pick is noticeably brighter than that.

Lowlight is a small menu bar app that adds extra steps under the macOS minimum, plus the normal range above it. You choose how many extra steps you want. It fades the backlight down and holds it at the step you pick. If you change the keyboard brightness in Control Center, macOS takes back over.

It uses private CoreBrightness APIs, so a future macOS update could break it. It's Apple Silicon only, needs macOS 26, is signed and notarized, and is MIT licensed. You can build it from source with ./build.sh.

I'm happy to answer questions about how it works, or to hear about other Macs it does or doesn't work on.