What are the standard ports for HTTP and HTTPS, and why does it matter?

HTTP defaults to port 80 and HTTPS to port 443, which is why you almost never type a port into a normal web address.

A port number tells a server which application should handle an incoming connection. Because HTTP and HTTPS have agreed-upon default ports, the browser supplies them silently, so these pairs are identical:

• http://example.com = http://example.com:80
• https://example.com = https://example.com:443

You only have to write the port when a server listens somewhere non-standard, which is common in development and for alternative servers:

• http://localhost:3000 — a typical dev server
• http://example.com:8080 — an alternative web server (e.g. Tomcat)

Memory aid: 80 = plain HTTP, 443 = secure HTTPS. A handy mnemonic: the "s" in https is the secure one, and 443 is its dedicated door.