What process is running on port 3000?

11 Sep 2025 09:54

Can’t start your Rails app because it’s already running but you can’t find it?

rola@INPAY-RNQP709MTC backend_v2 % sudo lsof -i :3000
COMMAND     PID USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
Microsoft 14734 rola   28u  IPv6 0xb9dec1e002660162      0t0  TCP localhost:63852->localhost:hbci (ESTABLISHED)
ruby      42857 rola   14u  IPv4 0x2e7917eea3a29d7b      0t0  TCP localhost:hbci (LISTEN)
ruby      42857 rola   16u  IPv6 0xfe39e6fb86a27f74      0t0  TCP localhost:hbci (LISTEN)
ruby      42857 rola   22u  IPv6 0x5c9b52f85ccf9a54      0t0  TCP localhost:hbci->localhost:63589 (CLOSED)
ruby      42857 rola   23u  IPv6 0xb5673178bc310d9b      0t0  TCP localhost:hbci->localhost:63590 (CLOSED)