Port 80 - HTTP Web Traffic

Protocol	TCP
Service	HTTP (Web)
Encrypted	No
IANA Status	Official

What is Port 80?

Port 80 is the default port for HTTP (Hypertext Transfer Protocol) traffic. When you visit a website using http://, your browser connects to port 80 unless otherwise specified.

Why Port 80?

Historical default: Assigned by IANA in the early days of the web
No port needed in URLs: http://example.com = http://example.com:80
Privileged port: Ports below 1024 require root/admin to bind

Security Considerations

HTTP is unencrypted

Data sent over port 80 can be intercepted. Always redirect to HTTPS (port 443) for production websites.

Common Uses

Redirecting HTTP to HTTPS
Let's Encrypt ACME challenges
Health checks behind load balancers
Internal services on private networks

Server Configuration

Nginx - Redirect to HTTPS

server {
    listen 80;
    server_name example.com;
    return 301 https://$server_name$request_uri;
}

Apache

<VirtualHost *:80>
    ServerName example.com
    Redirect permanent / https://example.com/
</VirtualHost>

Check if port 80 is in use

# Linux/macOS
sudo lsof -i :80
sudo ss -tlnp | grep :80

# Windows
netstat -ano | findstr :80

Troubleshooting

Port already in use: Check for Apache, Nginx, or other web servers
Permission denied: Need root/sudo to bind to port 80
Firewall blocking: Open port 80 in iptables/ufw

Port 80: HTTP Web Traffic