Fix "port 3000 is already in use" on Windows

You start your dev server and see:

Error: listen EADDRINUSE: address already in use :::3000

Something else is using the port. Often it is an old copy of the same server that never closed. Devpit finds it and stops it, after you say yes.

Open it from the main menu with 2, or choose Fix Stuck Ports & Apps. The section has three tools.

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Kill a port

Use this when you know the port number.

1. Choose Kill a port.

2. Type the port number, for example 3000. Digits only, from 1 to 65535.

3. Press Enter.

4. Devpit shows who is listening: the protocol, address, PID and program name.

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5. Read the question, for example “Kill node.exe (PID 12345) on port 3000?”. The default answer is No.

6. Press y to stop it.

7. Devpit waits up to two seconds and then tells you “Port 3000 is free”, or that it is still busy.

If nobody is using the port, Devpit says “Port 3000 is already free”. Then the error came from something else, such as a firewall or a typo in your config.

Kill the whole process tree

Dev servers are often started by another program. If Devpit sees that the parent is npm, pnpm, yarn, node, cmd or PowerShell, it shows an extra option:

[t] Kill process tree (also stops 2 other process(es) started by npm.exe)

Press t to switch it on before you answer. This stops the parent and everything it started. Use it when the server keeps coming back after you kill it.

Busy dev ports

Use this when you do not know which port is stuck.

1. Choose Busy dev ports.
2. Devpit checks every port on your dev list and shows the ones in use, with the PID, program and parent program.
3. Move with ↑ ↓ and mark rows with Space.
4. Press k to kill the marked ones. Answer the question.
5. Press r to refresh the list.

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The default list is 3000 to 3010, 4200, 5000, 5173, 5174, 8000, 8080, 8081, 8888, 9000 and 19000 to 19006 (the Expo range). You can change it in Settings.

Node processes

Use this to find stuck node, npm, pnpm and yarn programs that may not hold a port at all.

1. Choose Node processes.
2. Mark the ones to stop with Space.
3. Press k and answer the question.

What Devpit will never stop

Some processes are protected. Devpit shows a reason instead of a tick box and you cannot select them:

• PID 0 and PID 4 (the Windows System process),
• Windows services,
• every other program that lives in C:\Windows\System32.

The shells cmd.exe, powershell.exe and conhost.exe are the exception. They are not services, and dev tools start them constantly, so Devpit lets you stop them, mostly as part of a process tree.

Keys

Key	What it does
↑ ↓	Move
Enter	Choose a tool, or check the port you typed
Space	Mark or unmark a row
k	Kill the marked rows
t	Turn “kill process tree” on or off, when it is offered
r	Refresh the list
y / n	Answer the question (No is the default)
Esc	Go back

You can click rows and use the mouse wheel too. See Keyboard and mouse.

If Devpit says “needs admin”

Windows only lets you stop a program that runs with the same or lower rights than you. If the program was started as administrator, Devpit shows “needs admin” and does not stop it. Devpit does not raise its own rights for this.

1. Close the app the normal way, in its own window, or
2. Open a terminal as administrator, run devpit there, and try again.

Safety

Nothing is stopped without your confirmation, and the default answer is No. Devpit stops only the processes you picked. Stopping a program ends it right away, so save your work first. Dev servers can usually just be started again.