Find and Kill a Process on Mac

An app is frozen, a fan is spinning or something is eating memory. Here is how to find the process and end it without hitting the wrong one.

Activity Monitor

1. Open Activity Monitor (Spotlight → “Activity Monitor”).
2. Type the name in the search box, or sort by % CPU or Memory.
3. Select the process and click the ✕ button, then choose Quit. Choose Force Quit only if Quit does nothing.

Terminal: find the PID

pgrep -fl chrome
ps aux | grep -i chrome

pgrep -fl prints the PID and command line of every match. With ps aux | grep, ignore the line for grep itself.

To see details for one process:

ps -o pid,ppid,user,etime,%cpu,rss,command -p 12345

Terminal: end it

kill 12345        # SIGTERM: asks the process to quit and clean up
kill -9 12345     # SIGKILL: ends it immediately, no cleanup
killall Safari    # every process with that exact name

Always try plain kill first. kill -9 cannot save state and can leave lock files or half-written data behind. Be careful with pkill -f pattern and killall: they match more than you may expect.

The PID reuse trap

A PID is only a number. If a process exits and a new one starts, the new one can get the same PID. Between “I looked up the PID” and “I ran kill”, the number may belong to something else. Check again right before you kill, or use a tool that does it for you.

Why some kills fail

You can only signal processes owned by your own user. System daemons run as root, and kill says “Operation not permitted”. Ending those is rarely a good idea; do it deliberately with sudo.

With ProcessPeek

ProcessPeek lists your processes with their command line, parent, children and listening ports, so you can see what a process is before you end it. Kill Process confirms, re-checks that the PID is still the same process, asks it to quit, and only then offers an explicit Force Kill. See the ProcessPeek docs and how MacPeek kills safely.