Portero
See, control, and protect every port on your Mac.
Portero is a free, open source macOS app that shows which ports are open and which processes are using them in real time. It detects conflicts, lets you terminate processes with one click, block traffic through the built in Mac firewall, and open development servers directly in your browser. With a clear interface, Portero turns complex terminal commands into a simple way to monitor and manage ports.