Port 3001: Node.js / Next.js Fallback & Uptime Kuma — Secondary Node.js Dev Server, NestJS API & Uptime Kuma
Commonly used as the fallback port when Port 3000 is in use, or as the dedicated backend API port alongside a frontend on 3000. Inspect or free with `npx castov port 3001`.
How to Check & Kill Process on Port 3001 (EADDRINUSE Fix)
# Find process using port 3001 sudo lsof -i :3001 # Instantly kill process on port 3001 lsof -ti:3001 | xargs kill -9
# Find PID listening on port 3001 netstat -ano | findstr :3001 # Force kill by PID taskkill /PID <PID_NUMBER> /F
# Kill port 3001 via npx npx kill-port 3001 # Or diagnose via Castov CLI npx castov fix "EADDRINUSE :::3001"
# Test if port 3001 is reachable nc -zv localhost 3001 # Allow or deny port 3001 in UFW sudo ufw allow 3001/tcp
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Frequently Asked Questions about Port 3001
What is Port 3001 used for?
Port 3001 is the standard network port for Node.js / Next.js Fallback & Uptime Kuma (Secondary Node.js Dev Server, NestJS API & Uptime Kuma) operating over TCP. The typical system daemon or process is node.
How do I kill a process running on Port 3001 (EADDRINUSE)?
On macOS and Linux, run: lsof -ti:3001 | xargs kill -9 (or npx kill-port 3001). On Windows PowerShell/CMD, run: netstat -ano | findstr :3001 and then taskkill /PID <PID> /F.
Is it safe to expose Port 3001 to the internet?
Port 3001 has a Low security risk profile. Commonly used as the fallback port when Port 3000 is in use, or as the dedicated backend API port alongside a frontend on 3000. Inspect or free with `npx castov port 3001`.