How to keep your Mac awake with caffeinate

macOS ships with a built-in command called caffeinate that holds a software assertion preventing your Mac from sleeping — for as long as you leave it running. It's a precise, temporary tool: no permanent settings changed, no sudo required. This guide covers every useful variant, plus what to do when you don't want to keep a Terminal window open.

The basic command

Open Terminal (Applications > Utilities, or Spotlight: Cmd Space, type Terminal) and run:

# keep the Mac awake until you press Ctrl+C
caffeinate

The cursor will sit there doing nothing visible — that's correct. The command is running and holding the system awake. Press Ctrl+C to stop it. As soon as you stop it, normal sleep timers resume.

Caffeinate for a set duration

The -t flag takes a duration in seconds. This is the most useful form: you kick it off and forget about it, then it expires automatically.

# stay awake for 30 minutes (1800 seconds)
caffeinate -t 1800

# stay awake for 1 hour (3600 seconds)
caffeinate -t 3600

# stay awake for 2 hours (7200 seconds)
caffeinate -t 7200

Caffeinate flags — what each one does

Without any flags, caffeinate prevents idle system sleep but the display can still sleep. Add flags to widen what it blocks:

• -d — prevent display sleep. Use this for presentations or screen shares.
• -i — prevent idle system sleep (the default behaviour, stated explicitly).
• -s — prevent sleep when on AC power only. Ignored on battery.
• -m — prevent the disk from sleeping. Rarely needed but useful for long disk operations.

You can combine flags. For a one-hour session where you want both the display and the system awake:

# prevent display sleep AND system idle sleep for 2 hours
caffeinate -di -t 7200

Running caffeinate in the background

The drawback of the basic command is that it ties up your Terminal window — if you close the window, caffeinate stops. To run it in the background and keep your prompt free:

# run in background, stay awake 1 hour
caffeinate -t 3600 &

Bash will print something like [1] 48291 — that's the job number and PID. To stop it early:

# stop by job number (the [1] from the output above)
kill %1

# or stop by PID
kill 48291

If you've lost track of the PID, find it with:

# find running caffeinate processes
pgrep caffeinate

Caffeinate while a command runs

A tidy pattern: wrap a long-running command with caffeinate so the Mac stays awake exactly as long as the command takes, then sleeps normally:

# stay awake while a big rsync runs, then resume normal sleep
caffeinate rsync -av ~/Movies /Volumes/Backup

This is the cleanest approach for backups, video exports, or large uploads — no timer to guess, and no manual cleanup needed afterwards.

The limits of caffeinate

caffeinate is a Terminal tool, which means it requires you to keep either a Terminal window open (or remember the background job PID). It has no GUI, no status in the menu bar, and no easy way to tell at a glance whether it's still running. For occasional use that's fine. For something you do regularly — before a long meeting, a download, a remote connection — it becomes friction.

Caffeinate vs. changing pmset sleep settings

caffeinate and pmset both prevent sleep, but they work differently. caffeinate holds a temporary assertion — the moment it exits, normal sleep resumes with no cleanup needed. pmset -a sleep 0 changes a persistent system setting that stays until you change it back. For short-lived "keep me awake right now" needs, caffeinate is cleaner. For a Mac that should never sleep (a server, a download box), pmset is the right tool. See our guide on stopping your Mac from sleeping permanently for the pmset approach.