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Look up common TCP and UDP port numbers in your browser. Search by port, service, or category and see protocol, status, and use.
Protocol
IANA range
Category
443
HTTP over TLS. The default port for encrypted web traffic.
Also carries HTTP/2 and HTTP/3 (over QUIC, which uses UDP on the same port number). DoH (DNS over HTTPS) and many APIs are tunneled here because it is rarely blocked.
IANA port range
Well-known range (0 to 1023). Reserved for system services on most operating systems.
Browse 109 ports
Click any card for details
Port number ranges
0 to 1023
Well-known ports
Reserved for system services. Binding usually requires root or CAP_NET_BIND_SERVICE on Linux.
1024 to 49151
Registered ports
IANA records vendor and protocol assignments here. Most server applications listen in this range.
49152 to 65535
Dynamic / private
Operating systems pick ephemeral source ports from this range for outbound connections.
A TCP or UDP port is a 16-bit unsigned integer (0 to 65535) that identifies a specific service on a host. IANA maintains the authoritative Service Name and Transport Protocol Port Number Registry. This page lists the ports most commonly seen in production, along with their typical protocol, status, and use.
Port Number Lookup is a fast, offline-friendly reference for the TCP and UDP ports that show up most often in real production environments. Search by port number (try 443, 22, or 5432), by service name (ssh, postgres, mqtt), by protocol (TCP, UDP, or SCTP), by IANA range (well-known, registered, or dynamic), or by category (web, email, database, VPN, messaging, and more). Each entry explains what the port is for, which protocols it uses, whether it is officially registered with IANA or a de-facto convention, and the security or operational nuances most people care about: which mail submission port to use, why 25 is blocked by many ISPs, when DHCP needs both 67 and 68, why exposing 2375 or 6379 publicly is dangerous, and where modern alternatives like DoT (853), DoH (443), or WireGuard (51820) live. The page covers more than a hundred curated services across web, email, file transfer, remote access, databases, directories, messaging, media, VPN, and DevOps tooling. Copy the port number or the full port-plus-service string to your clipboard, or scan the cards to find the one you need. Everything runs in your browser. There is no signup and no network call to look anything up.
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