Port 443: HTTPS
Port 443 is HTTPS, encrypted web traffic secured by TLS. It is the default for essentially all modern websites and APIs, and increasingly carries HTTP/2 and HTTP/3 (over QUIC/UDP).
TCPWeb EncryptedIANA assigned
| Port number | 443 |
|---|---|
| Service | HTTP over TLS |
| Protocol | TCP |
| Category | Web |
| Default encryption | Yes (TLS/SSH) |
Frequently asked questions
What is port 443 used for?
Port 443 is HTTPS, encrypted web traffic secured by TLS. It is the default for essentially all modern websites and APIs, and increasingly carries HTTP/2 and HTTP/3 (over QUIC/UDP).
Is port 443 TCP or UDP?
Port 443 (HTTPS) uses TCP.
Is port 443 secure?
Yes. Port 443 carries encrypted traffic by default, so data in transit is protected.
Should I open port 443 on my firewall?
Only if you specifically need HTTPS. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.