PortPeek: See what's using your ports. Kill it in one click.
What is using port 3000?
The problem
“Port 3000 is already in use.” macOS gives you no screen that says which app owns a port, so you drop to Terminal, remember the right lsof flags, copy a PID and hope it is still the right process when you kill it.
The solution
PortPeek shows every listening port visible to your user with the process, PID and address behind it. Search by port, process or PID, and free a port without Terminal. It asks the process to quit gracefully first and re-checks the target so a reused PID is never killed by mistake.
Features
- Listening TCP and UDP ports, IPv4 and IPv6, with process, PID, address and state
- Instant search by port (partial too), process name, PID or address
- Safe kill: re-check → verify the same process → SIGTERM → confirm the port is free
- Explicit force kill only after a graceful attempt fails, with a second re-check
- Clear permission states: can terminate, permission required, protected
- Copy port, PID, process name or address; refreshes live only while its screen is open
How it works
- Open MacPeek and choose PortPeek.
- Search for the port or process, then select a row to inspect it.
- Kill Process: PortPeek verifies the target, asks it to quit, and confirms the port was released.
Installation
PortPeek is part of MacPeek. Install MacPeek, open Manage utilities and make sure PortPeek is switched on (it is on by default). There is nothing separate to download.
Privacy
What PortPeek reads:
- Listening sockets and the processes that own them, for your user account (via lsof)
Access it needs: None to view. You can terminate only processes your user owns.
Everything stays on your Mac: no account, no telemetry, no network access. Read the full privacy statement.
Open source
MacPeek and every utility in it are MIT-licensed. Read the code on GitHub, or see how a utility is built.
Related guides
- Find what is using a port on Mac
- Free port 3000 on Mac
- Kill a process on a port on Mac
- lsof on Mac: find process by port
Get PortPeek with MacPeek. Free and open source.