Fix “port already in use” (EADDRINUSE)

Your dev server won’t start because something is already on port 3000? Find it and stop it in under a minute.

1 min4 stepsmacOS · Linux · Windows

1
Find what is using the port
Replace 3000 with the port from your error message. The PID column is the process ID.
$lsof -i :
```
COMMAND   PID USER   FD   TYPE  NODE NAME
node    48213 you    23u  IPv6  TCP *:3000 (LISTEN)
```
Stop it gracefully
Use the PID from step 1. Most programs exit cleanly.
$kill
Still stuck? Force it
This one-liner finds and force-kills everything on the port.
$kill -9 $(lsof -ti :)
Force-kills without letting the program save. Check with lsof -i first.
On Windows
Run this in PowerShell instead.
PS>Stop-Process -Id (Get-NetTCPConnection -LocalPort ).OwningProcess -Force

Find what is using the port