Port 5001: Flask Fallback / Synology DSM / IPFS API — Python Flask Alternative Port (Avoiding macOS AirPlay on 5000)
Widely used by Python Flask/FastAPI developers on macOS because Apple AirPlay Receiver occupies port 5000 by default.
How to Check & Kill Process on Port 5001 (EADDRINUSE Fix)
# Find process using port 5001 sudo lsof -i :5001 # Instantly kill process on port 5001 lsof -ti:5001 | xargs kill -9
# Find PID listening on port 5001 netstat -ano | findstr :5001 # Force kill by PID taskkill /PID <PID_NUMBER> /F
# Kill port 5001 via npx npx kill-port 5001 # Or diagnose via Castov CLI npx castov fix "EADDRINUSE :::5001"
# Test if port 5001 is reachable nc -zv localhost 5001 # Allow or deny port 5001 in UFW sudo ufw allow 5001/tcp
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Frequently Asked Questions about Port 5001
What is Port 5001 used for?
Port 5001 is the standard network port for Flask Fallback / Synology DSM / IPFS API (Python Flask Alternative Port (Avoiding macOS AirPlay on 5000)) operating over TCP. The typical system daemon or process is python / gunicorn.
How do I kill a process running on Port 5001 (EADDRINUSE)?
On macOS and Linux, run: lsof -ti:5001 | xargs kill -9 (or npx kill-port 5001). On Windows PowerShell/CMD, run: netstat -ano | findstr :5001 and then taskkill /PID <PID> /F.
Is it safe to expose Port 5001 to the internet?
Port 5001 has a Medium security risk profile. Widely used by Python Flask/FastAPI developers on macOS because Apple AirPlay Receiver occupies port 5000 by default.