StillOn

What StillOn changes

macOS normally sleeps a notebook when its lid closes. StillOn is a small menu-bar utility for the specific case where the screen should turn off but the Mac still needs to finish work. It can be armed persistently from the menu bar or used once by holding Fn while closing the lid.

When armed, StillOn suppresses lid-close sleep, keeps the system available to the running task, locks the session, and asks the display to sleep. Opening the lid, quitting StillOn, restarting the Mac, or reaching the configured low-battery condition returns the machine to normal behaviour.

• Persistent mode from the menu-bar control.
• One-shot mode by holding Fn while closing the lid.
• No kernel extension and no administrator password required.
• Signed app updates are delivered through Sparkle.

Why it exists

Long coding-agent sessions, builds, downloads, and local automations do not fit neatly into the moment someone needs to leave a desk. Leaving the notebook open is an awkward workaround; standard keep-awake commands do not necessarily override the special lid-close sleep path.

StillOn focuses on that boundary. It is deliberately not a task runner or an agent dashboard. The job is to keep the Mac available so the tool already doing the work can continue and so an independently configured remote connection can remain reachable.

How the beta is being tested

The beta treats state restoration as a first-class requirement. It removes its sleep assertion when the lid reopens or the app exits, and includes an early display blank plus a heartbeat for dock and power-state transitions.

Physical lid tests still matter because this behaviour crosses macOS power management, hardware sensors, battery state, and any remote-access software the user relies on. The public guides document a cautious test sequence instead of presenting lid-closed operation as magic.

What the power study found

A replicated closed-lid screening compared StillOn, Clamshell, Amphetamine, Vorssaint, and supervised pmset on the same M4 MacBook Pro. Across three runs per condition, StillOn averaged 1.758 W. That was 39.3% below Clamshell, the next-lowest app, and 72.3% below pmset in this idle protocol.

StillOn was the only condition whose built-in display was reported asleep and whose session was locked throughout. The study publishes its method and data at stillon.dev/research/stillon-energy-efficiency. It is a builder-run, one-machine result, not a universal ranking or an AI-workload battery-life claim.