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Device guide — macOS

Keep a Mac screen awake

macOS separates display sleep from system sleep, and battery from charger. You can change the timers, run one Terminal command, or hold the screen open from a browser tab — here's when each makes sense.

Change the display-sleep timer

  1. Open System Settings → Lock Screen.
  2. Find “Turn display off on battery when inactive” and “on power adapter”.
  3. Choose a longer time, or Never. On most Macs, “Never” appears for the power-adapter setting — macOS protects battery life on the go.

Note that this controls the display. The separate “Put hard disks to sleep” and Power Nap options under Battery / Energy affect the machine itself.

The caffeinate command (no settings changed)

macOS ships with a tiny utility made for exactly this. Open Terminal and run:

caffeinate -d            # keep the display awake until you press Ctrl+C
caffeinate -d -t 3600    # ...but stop after 3600 seconds (1 hour)
caffeinate -dims         # display + system + disk, all held awake

It needs no admin password, leaves nothing running after it exits, and is ideal for “keep it awake until this finishes” jobs. Power users sometimes pair it with sudo pmset -a displaysleep 0 for a system-wide permanent change — overkill for most people.

Third-party menu-bar apps

Apps like Amphetamine wrap this same behavior in a menu-bar icon with schedules and triggers. They're a fine permanent solution — but if you only need it occasionally, a browser tab or caffeinate avoids installing anything at all.

The browser option (zero-install, zero-Terminal)

This site's tool holds a screen wake lock from Safari 16.4+, Chrome, Edge or Firefox on macOS. Same result as caffeinate -d for the display, controlled with one tap and an optional auto-stop timer. The tab must stay visible — hide it and macOS is free to sleep the screen again.

Mac-specific quirks worth knowing

  • Lid closed (clamshell). A MacBook stays awake with the lid shut only when connected to power and an external display (and keyboard/mouse). No software option changes that.
  • Low Power Mode. On battery, Low Power Mode shortens display-sleep timing and dims the panel — disable it for long always-on sessions.
  • Hot corners can sleep on purpose. If your screen “randomly” sleeps, check System Settings → Desktop & Dock → Hot Corners — a corner may be assigned to “Put Display to Sleep”.