How to troubleshoot port conflicts

A port conflict means something is already bound to that protocol and address.

Steps

1. List listeners with PortPilot (Ports or portpilot ports).
2. Confirm bind address. Two processes can share a port on different addresses.
3. Open the port → Diagnose. Health layers show whether the process is alive, the service is down, or a proxy/container is involved.
4. Stop the service, kill the process (ProcessGuard), or pick another port in your app.
5. If this happens often, use history to see which process usually owns it.

Docker published ports and reverse proxies often look like “mysterious” conflicts — enable Docker and proxy awareness rather than guessing.

Windows + Linux: same workflow. Download.