DevPortsBuy

Guides

Finding and stopping dev servers and leftover processes on macOS, from the terminal.

• How to find and kill the process using a port on a Mac

  Find what's listening on a port like 3000 with lsof, stop it safely with kill, and avoid the one-liners that also kill your browser or unrelated processes.

• Find and stop the dev servers your coding agent left running

  Claude Code, Codex, and Cursor start dev servers and watchers that outlive the session. How to find them on macOS, tell them apart from the agent's own tools, and stop them.