Why you cannot quit some processes on a Mac, and what to do instead
System processes run as root or their own users, and macOS restarts most of them anyway. Which ones you can quit, which you should not, and how to tell them apart.
Why can't I quit it?
Who owns it decides. Your apps run as you, and you can quit them. System services run as root or as their own user accounts, and quitting them needs administrator rights. Many are also restarted by launchd the moment they stop.
| Process on our Mac | Runs as | What happens if stopped |
|---|---|---|
| Google Chrome, editors, your apps | you | Quits |
| WindowServer | _windowserver | Logs you out |
| coreaudiod | _coreaudiod | Restarts at once; sound blips |
| mds_stores | _mds_stores | Restarts |
| opendirectoryd, backupd, syspolicyd | root | Restarts; what depended on it fails meanwhile |
| kernel_task | the kernel | Cannot be stopped |
ps -axo user,pid,comm | grep -i windowserver
sudo kill PIDWhat should I do instead?
- Your own app stuck: Force Quit from the Apple menu, or
killits process ID. - A system service misbehaving: restart the service by name where that is safe, such as
killall coreaudiodfor sound, or log out and in. - Something always returning: find what starts it; a LaunchAgent in
~/Library/LaunchAgentsis the usual answer for third party tools.
See it live
Free Mac's System tab offers Quit only where macOS allows it, and marks everything holding your login session as protected. See also how many processes run on a Mac and uninstalling Watchman for a LaunchAgent example.
Related: launchd high CPU and Which app is using the internet on my Mac.
Common questions
Why can't I quit a process on my Mac?
It is owned by root or a system user, or launchd restarts it. Only your own apps quit normally.
How do I kill a process in Mac Terminal?
kill followed by its process ID, or sudo kill for a system process. ps -ax lists IDs.
Is it safe to force quit system processes?
Usually not. Restart the service by name where that is safe, or log out and back in.