Port Number Lookup
Look up what a TCP or UDP port is used for — search 150+ common well-known and registered ports by number, service name or protocol. Instant and offline.
| Port | Protocol | Service | Description |
|---|---|---|---|
| 7 | tcp/udp | echo | Echo protocol |
| 19 | tcp/udp | chargen | Character generator protocol |
| 20 | tcp | ftp-data | FTP data transfer |
| 21 | tcp | ftp | FTP control (commands) |
| 22 | tcp | ssh | Secure Shell — remote login, SFTP, SCP, tunnels |
| 23 | tcp | telnet | Telnet — unencrypted remote login (legacy) |
| 25 | tcp | smtp | SMTP — mail transfer between servers |
| 37 | tcp/udp | time | Time protocol (legacy) |
| 43 | tcp | whois | WHOIS directory service |
| 49 | tcp/udp | tacacs | TACACS+ authentication |
| 53 | tcp/udp | dns | Domain Name System |
| 67 | udp | dhcp-server | DHCP / BOOTP server |
| 68 | udp | dhcp-client | DHCP / BOOTP client |
| 69 | udp | tftp | Trivial File Transfer Protocol |
| 79 | tcp | finger | Finger user-information protocol |
| 80 | tcp | http | HTTP — unencrypted web traffic |
| 88 | tcp/udp | kerberos | Kerberos authentication |
| 102 | tcp | iso-tsap | Siemens S7 / ISO-TSAP (industrial) |
| 110 | tcp | pop3 | POP3 — mail retrieval (plain) |
| 111 | tcp/udp | rpcbind | ONC RPC portmapper (NFS) |
| 113 | tcp | ident | Ident / auth protocol |
| 119 | tcp | nntp | NNTP — Usenet news |
| 123 | udp | ntp | Network Time Protocol |
| 135 | tcp/udp | msrpc | Microsoft RPC endpoint mapper |
| 137 | udp | netbios-ns | NetBIOS name service |
| 138 | udp | netbios-dgm | NetBIOS datagram service |
| 139 | tcp | netbios-ssn | NetBIOS session service (SMB over NetBIOS) |
| 143 | tcp | imap | IMAP — mail retrieval (plain) |
| 161 | udp | snmp | SNMP — network monitoring queries |
| 162 | udp | snmptrap | SNMP traps / notifications |
| 179 | tcp | bgp | Border Gateway Protocol (internet routing) |
| 194 | tcp | irc | Internet Relay Chat (official) |
| 201 | tcp/udp | at-rtmp | AppleTalk routing maintenance |
| 264 | tcp | bgmp | Border Gateway Multicast Protocol |
| 318 | tcp/udp | tsp | Time Stamp Protocol |
| 389 | tcp/udp | ldap | LDAP — directory services (plain) |
| 427 | tcp/udp | svrloc | Service Location Protocol |
| 443 | tcp | https | HTTPS — TLS-encrypted web traffic (also QUIC/HTTP3 on UDP) |
| 445 | tcp | microsoft-ds | SMB over TCP — Windows file sharing |
| 464 | tcp/udp | kpasswd | Kerberos password change |
| 465 | tcp | smtps | SMTP over implicit TLS (mail submission) |
| 500 | udp | isakmp | IKE key exchange for IPsec VPNs |
| 512 | tcp | exec | Remote process execution (legacy r-services) |
| 513 | tcp | login | rlogin (legacy) |
| 514 | udp | syslog | Syslog — remote logging |
| 515 | tcp | printer | LPD/LPR — line printer daemon |
| 520 | udp | rip | Routing Information Protocol |
| 521 | udp | ripng | RIPng (IPv6 routing) |
| 546 | udp | dhcpv6-client | DHCPv6 client |
| 547 | udp | dhcpv6-server | DHCPv6 server |
| 554 | tcp/udp | rtsp | Real Time Streaming Protocol (cameras, media) |
| 587 | tcp | submission | SMTP mail submission with STARTTLS (the modern sending port) |
| 593 | tcp | http-rpc-epmap | Microsoft RPC over HTTP |
| 631 | tcp/udp | ipp | Internet Printing Protocol (CUPS) |
| 636 | tcp | ldaps | LDAP over TLS |
| 646 | tcp/udp | ldp | MPLS Label Distribution Protocol |
| 853 | tcp | dns-over-tls | DNS over TLS (DoT) |
| 873 | tcp | rsync | rsync file synchronisation daemon |
| 902 | tcp | vmware-auth | VMware ESXi authentication |
| 989 | tcp | ftps-data | FTP over TLS — data |
| 990 | tcp | ftps | FTP over TLS — control |
| 993 | tcp | imaps | IMAP over TLS |
| 995 | tcp | pop3s | POP3 over TLS |
| 1080 | tcp | socks | SOCKS proxy |
| 1194 | tcp/udp | openvpn | OpenVPN |
| 1234 | tcp/udp | vlc | Common VLC / ad-hoc streaming port (unofficial) |
| 1241 | tcp | nessus | Nessus vulnerability scanner |
| 1311 | tcp | dell-openmanage | Dell OpenManage web console |
| 1433 | tcp | ms-sql-s | Microsoft SQL Server |
| 1434 | udp | ms-sql-m | Microsoft SQL Server browser/monitor |
| 1521 | tcp | oracle-db | Oracle database listener |
| 1701 | udp | l2tp | Layer 2 Tunneling Protocol (VPN) |
| 1723 | tcp | pptp | PPTP VPN (obsolete, insecure) |
| 1812 | udp | radius | RADIUS authentication |
| 1813 | udp | radius-acct | RADIUS accounting |
| 1883 | tcp | mqtt | MQTT — IoT messaging (plain) |
| 1900 | udp | ssdp | UPnP discovery (SSDP) |
| 2049 | tcp/udp | nfs | Network File System |
| 2082 | tcp | cpanel | cPanel (plain) |
| 2083 | tcp | cpanel-ssl | cPanel over TLS |
| 2086 | tcp | whm | WHM (plain) |
| 2087 | tcp | whm-ssl | WHM over TLS |
| 2121 | tcp | ftp-alt | Alternative FTP port |
| 2181 | tcp | zookeeper | Apache ZooKeeper client port |
| 2375 | tcp | docker | Docker daemon API (unencrypted — do not expose) |
| 2376 | tcp | docker-tls | Docker daemon API over TLS |
| 2483 | tcp | oracle-alt | Oracle DB listener (plain, alt) |
| 2484 | tcp | oracle-ssl | Oracle DB listener over TLS |
| 3000 | tcp | dev-http | Common dev-server port (Node, Rails, Grafana) |
| 3128 | tcp | squid | Squid HTTP proxy |
| 3260 | tcp | iscsi | iSCSI target |
| 3268 | tcp | gc-ldap | Active Directory global catalog (LDAP) |
| 3306 | tcp | mysql | MySQL / MariaDB database |
| 3389 | tcp/udp | rdp | Remote Desktop Protocol |
| 3478 | udp | stun | STUN/TURN — NAT traversal for VoIP/WebRTC |
| 3690 | tcp | svn | Subversion |
| 4369 | tcp | epmd | Erlang port mapper (RabbitMQ clustering) |
| 4500 | udp | ipsec-nat-t | IPsec NAT traversal |
| 4789 | udp | vxlan | VXLAN overlay networks |
| 5000 | tcp | upnp/dev | Flask dev server, Synology DSM, AirPlay receiver |
Showing the first 100 of 156 matches — refine your search to narrow down.
This is a reference table, not a port scanner — it does not probe anything. Ports 0–1023 are well-known, 1024–49151 registered, 49152–65535 dynamic/ephemeral.
What is the Port Number Lookup?
Port Number Lookup answers the question "what runs on port X? " instantly.
- 150+ common well-known and registered ports, IANA-derived
- Search by number (prefix matching) or by service name and description
- TCP / UDP protocol filter
- Covers web, mail, database, VPN, remote-access, IoT and gaming ports
- Explains the well-known / registered / ephemeral port ranges
- Works fully offline — it is a reference, not a scanner
How to use the Port Number Lookup
- 1
Type a port number or a service name into the search box.
- 2
Optionally filter by TCP or UDP.
- 3
Read the matching rows — port, protocol, service and what it is used for.
- 4
Clear the search to browse the full reference table.
About the Port Number Lookup
Port Number Lookup answers the question "what runs on port X?" instantly. Type a number like 443 or a service name like ssh and the embedded reference table filters live, showing the port, protocol, official service name and a practical description of what actually uses it.
The table covers the well-known and registered ports you meet in real work: web and mail ports, databases like MySQL, PostgreSQL, Redis and MongoDB, infrastructure like DNS, DHCP, SNMP and BGP, remote access like SSH, RDP and VNC, plus VPNs, messaging, game servers and container platforms. Protocol filtering separates TCP from UDP services.
This is a reference table, not a port scanner — it probes nothing and needs no network at all. The IANA-derived dataset ships inside the page, so lookups are instant, private and fully offline.
Frequently asked questions
What are well-known, registered and ephemeral ports?
Ports 0–1023 are well-known, reserved for core services like HTTP (80) and SSH (22), and traditionally need root to bind. Ports 1024–49151 are registered for specific applications with IANA, and 49152–65535 are dynamic or ephemeral — handed out temporarily to the client side of connections.
What is the difference between TCP and UDP on the same port number?
TCP and UDP have independent port spaces, so TCP 53 and UDP 53 are separate — DNS happens to use both. TCP gives reliable, ordered delivery for things like web pages and email, while UDP is a fire-and-forget datagram service used where speed beats reliability: DNS queries, VoIP, games and streaming.
Can this tool check whether a port is open on my machine?
No — it is a reference table, not a scanner, and browser pages cannot open raw sockets to probe ports anyway. To test open ports use netstat or ss locally, or a network scanner like nmap from another machine. This tool tells you what a port number means once you have found it.
Why isn't the port I searched for listed?
The table carries the few hundred ports people actually look up, not all 65,536. An unlisted number may still be a legitimately registered port, a vendor-specific choice or an ephemeral client port. High random numbers in netstat output are usually ephemeral ports and rarely meaningful by themselves.
Which ports should never be exposed to the internet?
Database and management ports top the list: Redis (6379), MongoDB (27017), MySQL (3306), PostgreSQL (5432), memcached (11211), unencrypted Docker (2375), SMB (445) and RDP (3389) are the classic sources of breaches when left open. Put them behind a VPN or firewall and expose only what must be public.
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