- Port
- 443
- Protocol used by the service
- TCP/UDP
- IANA registrations
- TCP/UDP/SCTP
- Encryption
- Encrypted
- IANA description
- http protocol over TLS/SSL
- IANA service name
- https
Note: IANA has formally registered HTTPS on TCP/UDP/SCTP, but in real-world practice this service operates over TCP/UDP only — a formal registration on a transport doesn't guarantee the protocol is actually implemented or used over it. This page's Protocol field reflects genuine usage, not just the registry entry.
What port 443 is used for
Encrypted web traffic — the standard port for essentially all modern website traffic, plus increasingly other protocols (like HTTP/3 and DNS-over-HTTPS) that deliberately reuse it to blend in with ordinary web traffic and avoid being blocked by network filtering.
Is port 443 encrypted?
Encrypted via TLS by design — this is the baseline expectation for any public-facing website today.
Firewall & exposure considerations
The standard port to expose publicly for a website. Keep TLS configuration and certificate renewal current; an expired certificate or weak cipher configuration undermines the protection this port is specifically meant to provide.
Related ports
References
- RFC 9110 — HTTP Semantics
- RFC 8446 — The Transport Layer Security (TLS) Protocol Version 1.3
- RFC 9114 — HTTP/3
- IANA registration for port 443
Look up any other port
Search the full IANA registry — all 6,100+ ports and 12,500+ protocol-specific records — on the Port Lookup tool.
Last reviewed: . Data source: IANA Service Name and Transport Protocol Port Number Registry. Security and usage notes are this site's own editorial content, not official IANA data.