# What's using port 3000 on my Mac? (and how to free it)

Usually an old dev server you forgot. OneMacTools' Dev & Agents shows every dev server by project with its ports, and answers “what's on port 3000?” with the program, folder and who started it, plus a Stop button.

## With OneMacTools
1. Open OneMacTools › Dev & Agents › Dev Servers.
2. Type the port in “What's on port…”.
3. Check the command and project folder, then click Stop… (it asks first).

## With Terminal
Run lsof -nP -iTCP:3000 -sTCP:LISTEN to see the process id, then kill <pid>. OneMacTools does the same, and also shows the project and what started it.


## Stop it happening
The runaway-process watchdog notifies you when a dev server has sat idle for a day, and can stop it after the time you set.


## Questions
**What's on ports 5000 and 7000 on a Mac?**
AirPlay Receiver (Control Center). Turn it off in System Settings › General › AirDrop & Handoff if you need those ports.

**Is it safe to kill a process using a port?**
If it's your own dev server, yes; it just stops. Don't stop system processes; OneMacTools only offers Stop for your own processes.

Source: https://www.onemactools.com/guides/whats-using-a-port-on-mac (updated 2026-10-14)