Mac

lsof -i -P | grep "3000"

kill -9 PID

killall mongod

Windows

netstat -a -o | find "3000"

Taskkill /IM chrome.exe /F

where /F is used to kill the process forcefully. You can also kill any particular process by using it’s ID, the tasklist command displays the process ID’s as well (you can see the PID column in the screenshot). To kill any process using it’s ID, run the command as:

Taskkill /PID 2704 /F

Now to kill multiple processes simultaneously, run the above command with the PID’s of all the processes followed by spaces

Taskkill /PID 2704 5472 4344 /F