See what holds a port and stop it from a Stream Deck key
To fix port 3000 already in use on Windows, add Port Killer for Windows to your Stream Deck and put the port on a Port Watch key. The key shows which program holds the port, and two presses stop that program and everything it started, clearing EADDRINUSE for Node.js, Vite, Python, Java or any other local dev server without netstat or Task Manager.
Stream Deck plugin · Works on Windows 10 or later with the Stream Deck app 6.9 or later.
What you can do
See who holds a port: one key per port, green when nothing listens on it, red with the program's name and PID when something listens on it (IPv4 and IPv6).
Stop it on purpose: the first press asks STOP? and a second press within 2 seconds confirms; a single press never stops anything.
Clear the whole server: it stops the whole process tree, so watchers and child processes cannot keep holding the port.
Stop only what you saw: it checks the port again just before stopping and stops nothing if another program has taken it.
Stay safe: Windows system processes (System, svchost, services, lsass, wininit, csrss, smss and others), the Stream Deck app and the plugin itself are never stopped.
Watch all your dev ports: Dev Ports shows how many are in use (by default 3000-3010, 4200, 5000, 5173, 8000, 8080, 8888, or your own list); press to step through them.
Runs entirely on your PC: no account, no online service, no telemetry.
English and Japanese.
How it works
Install the plugin from the Elgato Marketplace. In the Stream Deck app, drag Port Watch onto a key.
In the key's settings, enter the port, for example 3000.
When the key turns red, press it once to see STOP?, then press again within 2 seconds. The key turns green when nothing listens on the port any more.
The plugin uses the Windows tools netstat, tasklist and taskkill with the Stream Deck app's permissions.
Put a Port Watch key for port 3000 on your Stream Deck. When the key is red, it shows the program and its PID; press once to see STOP?, then again within 2 seconds, and that program and everything it started are stopped.
Will it stop the watchers and child processes too?
Yes. It stops the whole process tree, so watchers and child processes cannot keep holding the port.
Can I see all my dev ports at once?
Yes. A Dev Ports key shows how many of your dev ports are in use and steps through them when you press it. It never stops anything; use a Port Watch key for that.
Can it stop something important by mistake?
It never stops Windows system processes, the Stream Deck app or itself, and it checks the port again just before stopping, so it stops nothing if another program has taken the port.
Why does the key say NOT STOPPED?
Windows refused to stop the program, most often because it runs as administrator while the Stream Deck app does not. Stop it from where you started it.
Limits
It never asks for administrator rights, so it cannot stop a server started as administrator.
If something outside the stopped tree restarts the server (for example a process manager or a Windows service), stop that manager instead.
Ports published by Docker Desktop or WSL are held by Windows helper processes; stop the container instead.
