How to Find and Free Used Ports on Mac with lsof and kill Commands
Learn how to use lsof on macOS to check which TCP ports are in use and safely kill processes with the kill command. A practical guide for developers to fix port already in use errors.
Check Used Ports on Mac
You can use the lsof command on Mac to check which ports are currently in use.
lsof -i tcp:<PORT>After running the command, your terminal will display information similar to the example below. What we need here is the PID (Process ID).
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
node 41303 chia1104 20u IPv6 0x58ddc79557aad159 0t0 TCP *:hbci (LISTEN)Next, you can terminate the process by entering this command in the terminal:
kill -9 <PID>The -9 flag will immediately force the process to stop without giving it a chance to clean up.
If you want to allow the process to close gracefully, use -15 (TERM) or -3 (QUIT) instead.
Alternative
You can also kill multiple ports at once with a single command:
kill -9 $(lsof -ti:3000,3001)Written by: Chia1104 CC BY-NC-SA 4.0