Caffeinate your Mac to prevent it from sleeping

Source: Dev.to

Originally posted on my blog.

TL;DR

I’ll show you how to use macOS’s built-in caffeinate command to keep your Mac awake:

• until you stop it
• for a set amount of time, or
• only while a long‑running command is executing

No additional apps, no menu‑bar junk, no “why is my Mac sleeping again?!” drama.

Why you’d care about caffeinate

If you’ve ever kicked off a long download, rsync backup, Docker build, video export, or “I’ll just run this migration quickly” job… and then came back to find your Mac politely sleeping like an innocent kitten — you already know why this matters.

macOS has an official tool for this, and it’s been sitting right under your nose:

caffeinate

It’s basically the Terminal equivalent of “No, macOS, we are not done here.”

Option #0: The simplest possible usage

Open Terminal and run:

caffeinate

Your Mac won’t go idle‑sleep as long as this process is running.
To stop it, press Ctrl + C.

Option #1: Keep the Mac awake for a fixed amount of time

Pass the -t parameter (seconds) to specify a duration:

caffeinate -t 7200   # 2 hours

Common values:

Option #2: Keep the display awake as well

Use the -d switch to prevent the display from dimming:

caffeinate -d

Option #3: Keep Mac awake only while a command runs

Wrap your long‑running command with caffeinate -i:

caffeinate -i your_command_here

Examples

caffeinate -i rsync -av ~/Pictures/ /Volumes/Backup/Pictures/

caffeinate -i npm run build

caffeinate -i ./run-tests.sh

When the wrapped command finishes, caffeinate stops automatically—no cleanup required.

Option #4: Run caffeinate in the background

If you want to keep your Terminal usable:

caffeinate -d -i &

You can verify it’s running:

ps aux | grep caffeinate

Stop it

• Bring it to the foreground and press Ctrl + C:

  fg

• Or kill it by PID (shown in the ps output):

  kill 

Handy flag cheat sheet

Bonus: a tiny alias (because typing is hard)

Add this to your ~/.zshrc (or ~/.bashrc):

alias awake='caffeinate -d -i'

Reload the shell configuration:

source ~/.zshrc

Now you can run:

awake rsync -av ~/Stuff/ /Volumes/Backup/Stuff/

…and your Mac stays awake while the command runs.

Hope this was useful! 💪