Portis
Port 5000 or 7000 in Use on a Mac? It's AirPlay Receiver
Port 5000 in use on your Mac? It's ControlCenter running AirPlay Receiver. Confirm it with lsof, turn it off in System Settings, or run Flask on 5001.
Notes on ports and processes.
Short posts for Mac developers about finding and freeing ports, tested on macOS 27.
netstat Not Showing Ports on macOS 27: What Changed, What Works
On macOS 27, netstat -an can list no TCP or UDP sockets at all. Why that happens, and the lsof and nettop commands that still show every listening port.
lsof Cheat Sheet for Mac: Ports, PIDs, Listeners and Gotchas
An lsof cheat sheet for Mac: list listening ports, find the process on a port, get its PID, folder and command line. Every command tested on macOS 27.2.
How to Kill a Process on a Port on Mac (Safely, and for Good)
Kill the process on a port on a Mac with lsof and kill: SIGTERM first, kill -9 only when needed, and what to do when launchd, pm2 or Docker restarts it.
What Is rapportd? The Apple Processes Listening on Your Mac
What is rapportd, why ControlCenter holds ports 5000 and 7000, and what mDNSResponder does: each Apple process listening on your Mac, its port and its switch.