How do I fix this instantly in my terminal?

On macOS & Linux run: "kill -9 $(lsof -t -i:3000)". On Windows PowerShell run: "Stop-Process -Id (Get-NetTCPConnection -LocalPort 3000).OwningProcess -Force". This terminates the conflicting process or resets the state without rebooting your computer.

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Port & Network Error

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

Developer guide and instant terminal command to diagnose and solve this error.

Terminal Output

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

Why Does This Error Happen?

Another process (usually an orphaned Node.js, Next.js, or React process) is already listening on local port 3000.

Instant Terminal One-Liner Fixes

Choose your operating system

Linux (Bash / Zsh)

kill -9 $(lsof -t -i:3000)

macOS (Terminal / iTerm2)

kill -9 $(lsof -t -i:3000)

Windows (PowerShell Run as Administrator)

Stop-Process -Id (Get-NetTCPConnection -LocalPort 3000).OwningProcess -Force

Comprehensive Step-by-Step Resolution

1Identify the process ID (PID) occupying port 3000.
2Terminate the process using the kill command below.
3Alternatively, run your application on a different port like 3001 using "PORT=3001 npm run dev".

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