HTTP
What is Port 80?
Port 80 is the default port for the Hypertext Transfer Protocol (HTTP), the foundation of data communication on the World Wide Web. Developed by Tim Berners-Lee at CERN and standardized in RFC 2616 (HTTP/1.1) and later RFC 7540 (HTTP/2), HTTP defines how messages are formatted and transmitted between web browsers and servers. When you type a URL into your browser without specifying a port, it connects to port 80 by default. HTTP is a stateless, request-response protocol that supports methods like GET, POST, PUT, DELETE, and more. While HTTPS (port 443) has become the standard for secure web traffic, port 80 remains in widespread use for redirecting to HTTPS, serving non-sensitive content, and running internal web applications. Every major web server — Apache, Nginx, IIS, Caddy — listens on port 80.
Common Uses
- Serving web pages and web applications
- HTTP-to-HTTPS redirects
- REST API endpoints (non-encrypted)
- Internal web dashboards and admin panels
- Health check endpoints for load balancers
Technical Details
Copy-paste commands to check port 80 (HTTP) from your terminal
Test connectivity
nc -zv example.com 80
curl -v --max-time 5 http://example.com:80/
telnet example.com 80
nmap -p 80 -sV example.com
(echo > /dev/tcp/example.com/80) 2>/dev/null && echo "open" || echo "closed"
Open port in firewall
sudo ufw allow 80/tcp
sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
sudo firewall-cmd --permanent --add-port=80/tcp && sudo firewall-cmd --reload
Security Considerations
HTTP transmits all data in plaintext, including cookies, form data, and potentially passwords. Modern best practice is to redirect all port 80 traffic to HTTPS on port 443. Port 80 is a primary target for web application attacks including SQL injection, XSS, and directory traversal. Use a WAF, keep web server software updated, and always enforce HTTPS for sensitive data.
Popular Ports Reference
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