PORT 8888 / TCPDev & LocalhostExposure Risk: Medium

Port 8888: Jupyter Notebook — JupyterLab & Interactive Python Notebooks

Default local web server port for Jupyter Notebook and JupyterLab data science environments.

Default Service

Jupyter Notebook

Process: jupyter-notebook

Transport Protocol

TCP

IANA Registered Port 8888

Docker Port Flag

-p 8888:8888

Container to Host Mapping

How to Check & Kill Process on Port 8888 (EADDRINUSE Fix)

macOS & Linux (lsof / kill)

# Find process using port 8888
sudo lsof -i :8888

# Instantly kill process on port 8888
lsof -ti:8888 | xargs kill -9

Windows (PowerShell & CMD)

# Find PID listening on port 8888
netstat -ano | findstr :8888

# Force kill by PID
taskkill /PID <PID_NUMBER> /F

Cross-Platform Node.js One-Liner

# Kill port 8888 via npx
npx kill-port 8888

# Or diagnose via Castov CLI
npx castov fix "EADDRINUSE :::8888"

Linux Firewall (UFW) & Connectivity Test

# Test if port 8888 is reachable
nc -zv localhost 8888

# Allow or deny port 8888 in UFW
sudo ufw allow 8888/tcp

Frequently Asked Questions about Port 8888

What is Port 8888 used for?

Port 8888 is the standard network port for Jupyter Notebook (JupyterLab & Interactive Python Notebooks) operating over TCP. The typical system daemon or process is jupyter-notebook.

How do I kill a process running on Port 8888 (EADDRINUSE)?

On macOS and Linux, run: lsof -ti:8888 | xargs kill -9 (or npx kill-port 8888). On Windows PowerShell/CMD, run: netstat -ano | findstr :8888 and then taskkill /PID <PID> /F.