Sinatra Dev Server
What is Port 4567?
Port 4567 is the default port for Sinatra, a lightweight Ruby web framework used for building simple web applications and APIs. Sinatra is known for its minimalist approach — a basic web application can be created in just a few lines of Ruby code. When you run a Sinatra application without specifying a port, it starts on port 4567. Beyond Sinatra, this port is sometimes used by other development tools and lightweight web services. Sinatra has influenced many other micro-frameworks in different languages, including Flask (Python), Express (Node.js), and Spark (Java). It remains popular for prototyping, small APIs, and as an embedded web server in larger applications.
Common Uses
- Sinatra web application development
- Ruby microservice and API development
- Prototyping and proof-of-concept applications
- Embedded web interfaces in Ruby applications
Technical Details
Copy-paste commands to check port 4567 (Sinatra Dev Server) from your terminal
Test connectivity
nc -zv example.com 4567
curl -v --max-time 5 http://example.com:4567/
telnet example.com 4567
nmap -p 4567 -sV example.com
(echo > /dev/tcp/example.com/4567) 2>/dev/null && echo "open" || echo "closed"
Open port in firewall
sudo ufw allow 4567/tcp
sudo iptables -A INPUT -p tcp --dport 4567 -j ACCEPT
sudo firewall-cmd --permanent --add-port=4567/tcp && sudo firewall-cmd --reload
Security Considerations
Sinatra development servers should not be used in production without a proper web server (Puma, Unicorn) behind a reverse proxy. Bind to localhost during development. In production, run behind Nginx or Caddy on ports 80/443 with proper TLS, rate limiting, and security headers.
Popular Ports Reference
The most commonly used and referenced network ports