You dragged the keyboard brightness slider all the way down. It's still glowing. In a dark room, the lowest setting macOS allows is bright enough to light up your desk, and the only step below it is off. Then you can't see the keys at all.
This guide covers every keyboard brightness control that macOS actually gives you, and then the one way to go below Apple's floor on an Apple Silicon MacBook.
Open System Settings > Keyboard and drag the Keyboard Brightness slider. Dragging it fully left turns the backlight off. There is no position between "dimmest allowed" and "off".
Go to System Settings > Control Center and enable Keyboard Brightness. You get the same slider one click away in your menu bar. Convenient, but the same floor applies.
macOS raises keyboard brightness on its own in low light, which is exactly when you want it dim. Turn off "Adjust keyboard brightness in low light" in System Settings > Keyboard so your manual setting sticks.
In the same settings pane you can have the backlight turn off after a period of inactivity. This helps battery life but does nothing about brightness while you type.
That's the complete list. None of these gets you below the minimum, because the limit isn't in the settings. It's a floor value macOS enforces on the hardware. We wrote about why Apple locks the keyboard backlight floor if you're curious about the internals.
The backlight hardware in Apple Silicon MacBooks supports dozens of brightness steps below the macOS floor. The keys can glow far dimmer than Apple lets you set. Midnight Keyboard is a menu bar app that unlocks them:
It works on any Apple Silicon MacBook running macOS 14 or later. No system modifications, no disabling SIP, nothing to configure.
Free 3-night trial, no account required.
Download Midnight Keyboard$7 one-time to unlock after trial. macOS 14+, Apple Silicon only.
Apple never documented a reason, but the most likely explanation is PWM flicker sensitivity at very low duty cycles. The full story is in Why Apple Won't Let You Dim Your Keyboard.
No. Midnight Keyboard controls the built-in backlight of Apple Silicon MacBooks. External keyboards, including Apple's Magic Keyboard, have their own controllers.
Yes. Midnight Keyboard reapplies your chosen level when your Mac wakes from sleep, and with Launch at Login enabled it restores it after a restart too.