port 443
Port 443 is the IANA well-known port reserved for encrypted web traffic: today it answers over both TCP, with classic TLS, and UDP, with QUIC.
Searching by the exact number gives the highest match score (exact match), which is why the single result surfaces first even with the catalog full of other ports.
The two ports share the category because the difference between them is the encryption layer, not the function.
Anyone also serving QUIC needs a second explicit rule for UDP/443, TCP and UDP do not share the same state table.
Deliberate decision: unauthorized port scanning is an abuse vector and has legal implications in several countries. We prefer a clear, safe reference.
Both today: classic HTTPS (HTTP/1.1 and HTTP/2 over TLS) uses TCP/443, while HTTP/3 uses QUIC over UDP/443. A modern server usually listens on both, and the browser prefers UDP when available, falling back to TCP automatically.
Because 443 is the implicit default port for any URL starting with `https://`. You only need to type the port when the server listens on a different one, like 8443, a common case for admin dashboards.
No. SNI (Server Name Indication) tells the server which domain the client wants, allowing multiple certificates on the same IP and port 443. ALPN, negotiated in the same handshake, picks the application protocol, HTTP/1.1 or HTTP/2. They are two independent TLS extensions that work together.
Encrypted web (TLS 1.2/1.3). Also used by HTTP/3 over QUIC (UDP 443).
Everything runs locally in your browser from an embedded catalog. This tool does not connect to IPs or ports, it is not a scanner.