Default Port for HTTPS: Port 443 Explained for Testers

The default port for HTTPS is 443. RFC 9110 defines it: when an https:// URL has no port, the client connects to TCP port 443. Plain HTTP uses port 80. Both numbers are registered with IANA.

So https://www.softwaretestpilot.com/ and https://www.softwaretestpilot.com:443/ point to exactly the same place. The port is only hidden, not missing.

An IP address finds the machine; a port finds the program on that machine. One server can run a web server on 443, a database on 5432 and an SSH service on 22 at the same time. The number after the colon in a URL (host:8443) tells the client which program to talk to. When you leave it out, the scheme (http or https) decides the default.

Only 443 and 80 are true standards here. The others are common habits, not rules, so always check the environment's own documentation.

These commands were run on 6 Nov 2026 against this site. Your timings and headers will differ.

# 1. HTTPS with no port: curl uses 443
curl -sv https://www.softwaretestpilot.com/ -o /dev/null
# response line: < HTTP/2 200

# 2. The same URL with :443 written out gives the same result
curl -sv https://www.softwaretestpilot.com:443/ -o /dev/null
# response line: < HTTP/2 200

# 3. Plain HTTP goes to port 80 and is redirected
curl -sI http://www.softwaretestpilot.com/
# HTTP/1.1 301 Moved Permanently

Run with -v and look for the "Connected to ... port 443" line to confirm which port was used. The redirect in step 3 is the behaviour you want: visitors who type http:// are sent to the secure version.

1. HTTP redirects to HTTPS. http://host/path returns 301 or 308 to https://host/path with the path and query kept.
2. Explicit :443 works. https://host:443/ gives the same response as https://host/.
3. No mixed content. The HTTPS page loads no scripts or images over http:// (check the browser console).
4. Wrong port fails cleanly. http://host:443/ should not return private data; expect an error or a 400 response.
5. Non-default ports are closed if unused. A production host should not expose dev ports like 8080 or 3000 to the internet.
6. Links and redirects keep the right port. On a staging server at :8443, login redirects must not drop the port and send you to 443.
7. Certificate is valid on that port. The certificate matches the host name and is not expired.

Q: What is the default port for HTTPS?

Sample answer: "443. HTTP uses 80. If an https URL has no port, the client connects to 443, so the browser hides it. Anything else, like 8443 on a staging server, has to be written in the URL. As a tester I also check that port 80 redirects to HTTPS and that no dev ports are left open in production."

Likely follow-ups: What does HTTPS add on top of HTTP? (TLS encryption and server identity.) Does HTTP/3 use 443? (Yes, but over UDP; see RFC 9114.) What happens if you send HTTP to 443? (The TLS handshake fails or the server returns an error.)

Pick any public HTTPS site. Using curl or your browser's Network tab, find: (1) which port was used, (2) whether http:// redirects, and (3) which status code the redirect uses.

Answer check: the port should be 443, and the redirect should be 301 or 308 pointing to the https:// address with the same path.

Ports are the first step of every request. Next, learn what the response codes mean in 401 vs 403 for unauthorized requests, run eight hands-on checks in how to test a REST API online, or try requests yourself in the API Playground. Questions? Ask in the QA Community.