Port Number Reference
NewComplete reference for well-known and registered TCP/UDP port numbers: protocol, transport, range classification, and usage. Searchable and filterable. No signup required.
Showing 41 of 41 ports
| Port | Protocol | TCP/UDP | Range | Description |
|---|---|---|---|---|
| 20 | FTP (Data) | TCP | Well-Known | FTP data transfer in active mode. Increasingly replaced by SFTP/FTPS. |
| 21 | FTP (Control) | TCP | Well-Known | FTP command/control channel used to authenticate and issue commands. |
| 22 | SSH | TCP | Well-Known | Secure Shell — encrypted remote login, command execution, and SFTP/SCP file transfer. |
| 23 | Telnet | TCP | Well-Known | Unencrypted remote terminal access. Considered insecure; replaced by SSH. |
| 25 | SMTP | TCP | Well-Known | Simple Mail Transfer Protocol — sending email between mail servers. |
| 53 | DNS | TCP/UDP | Well-Known | Domain Name System queries (UDP for lookups, TCP for zone transfers/large responses). |
| 67 | DHCP (Server) | UDP | Well-Known | DHCP server listens here to hand out IP address leases to clients. |
| 68 | DHCP (Client) | UDP | Well-Known | DHCP client listens here for offers/acknowledgements from the server. |
| 69 | TFTP | UDP | Well-Known | Trivial File Transfer Protocol — simple, unauthenticated file transfer, often for network boot. |
| 80 | HTTP | TCP | Well-Known | Unencrypted web traffic. Modern sites typically redirect this to HTTPS (443). |
| 110 | POP3 | TCP | Well-Known | Post Office Protocol v3 — downloads email from a mail server to a client. |
| 119 | NNTP | TCP | Well-Known | Network News Transfer Protocol — used by Usenet newsgroups. |
| 123 | NTP | UDP | Well-Known | Network Time Protocol — synchronizes system clocks over a network. |
| 143 | IMAP | TCP | Well-Known | Internet Message Access Protocol — manages email on the server (unlike POP3, which downloads it). |
| 161 | SNMP | UDP | Well-Known | Simple Network Management Protocol — monitoring and managing network devices. |
| 162 | SNMP Trap | UDP | Well-Known | Receives asynchronous SNMP trap notifications from managed devices. |
| 179 | BGP | TCP | Well-Known | Border Gateway Protocol — exchanges routing information between internet routers. |
| 389 | LDAP | TCP/UDP | Well-Known | Lightweight Directory Access Protocol — queries directory services (e.g. user accounts). |
| 443 | HTTPS | TCP | Well-Known | HTTP encrypted with TLS/SSL. The standard port for secure web traffic. |
| 445 | SMB | TCP | Well-Known | Server Message Block — Windows file and printer sharing. |
| 465 | SMTPS | TCP | Well-Known | SMTP submission over an implicit TLS connection. |
| 514 | Syslog | UDP | Well-Known | Sends system log messages to a centralized logging server. |
| 587 | SMTP (Submission) | TCP | Registered | Standard port for email clients to submit outgoing mail, typically with STARTTLS. |
| 636 | LDAPS | TCP | Well-Known | LDAP encrypted with TLS/SSL. |
| 993 | IMAPS | TCP | Well-Known | IMAP encrypted with TLS/SSL. |
| 995 | POP3S | TCP | Well-Known | POP3 encrypted with TLS/SSL. |
| 1433 | Microsoft SQL Server | TCP | Registered | Default port for Microsoft SQL Server database connections. |
| 1521 | Oracle DB | TCP | Registered | Default listener port for Oracle Database connections. |
| 1723 | PPTP | TCP | Registered | Point-to-Point Tunneling Protocol — legacy VPN protocol, considered insecure. |
| 3306 | MySQL / MariaDB | TCP | Registered | Default port for MySQL and MariaDB database connections. |
| 3389 | RDP | TCP | Registered | Remote Desktop Protocol — Windows remote graphical desktop access. |
| 5432 | PostgreSQL | TCP | Registered | Default port for PostgreSQL database connections. |
| 5672 | AMQP | TCP | Registered | Advanced Message Queuing Protocol — used by RabbitMQ and other message brokers. |
| 5900 | VNC | TCP | Registered | Virtual Network Computing — remote graphical desktop sharing. |
| 6379 | Redis | TCP | Registered | Default port for the Redis in-memory data store. |
| 8080 | HTTP (Alternate) | TCP | Registered | Common alternate port for HTTP, often used by proxies and dev servers. |
| 8443 | HTTPS (Alternate) | TCP | Registered | Common alternate port for HTTPS, often used by app servers and admin panels. |
| 9200 | Elasticsearch | TCP | Registered | Default REST API port for Elasticsearch. |
| 9092 | Kafka | TCP | Registered | Default broker port for Apache Kafka. |
| 27017 | MongoDB | TCP | Registered | Default port for MongoDB database connections. |
| 49152–65535 | Dynamic / Private | TCP/UDP | Dynamic / Private | Ephemeral ports assigned temporarily by the OS for outgoing client connections. |
About this tool
A port number identifies a specific process or service on a device, allowing a single IP address to handle many simultaneous network connections—web traffic on 443, email on 25, SSH on 22, and so on. IANA (the Internet Assigned Numbers Authority) divides the full 0–65535 range into three bands: well-known ports (0–1023), reserved for core, long-established services and requiring administrative privileges on most operating systems; registered ports (1024–49151), used by specific applications and vendors but not requiring special privileges; and dynamic or private ports (49152–65535), assigned temporarily by the operating system for outgoing client connections. This page is a searchable reference for the ports developers and sysadmins encounter most often.
How to use
- 1Use the search box to filter by port number, protocol name, or keyword (e.g. "database", "mail").
- 2Click a range filter (Well-Known, Registered, Dynamic) to narrow the list to that band.
- 3Check the TCP/UDP column to see which transport protocol a service uses—some, like DNS, use both.
Frequently asked questions
- What is the difference between TCP and UDP?
- TCP (Transmission Control Protocol) is connection-oriented and guarantees ordered, reliable delivery—used for HTTP, SSH, and databases. UDP (User Datagram Protocol) is connectionless with no delivery guarantee, but has lower overhead—used for DNS lookups, video streaming, and online gaming, where speed matters more than guaranteed delivery.
- Why do some services need administrator/root privileges to use their port?
- On Linux and macOS, binding to a well-known port (0–1023) requires elevated privileges, a security convention that prevents ordinary users from impersonating standard services like HTTP (80) or SSH (22). Ports 1024 and above can be used by any user process.
- What are ephemeral (dynamic) ports?
- When your computer initiates an outgoing connection—like a browser connecting to a website—the operating system assigns it a temporary port from the dynamic range (49152–65535) for the duration of that connection. This is why you never have to configure a port for outgoing requests; it's chosen automatically and released when the connection closes.
- Can two applications use the same port number?
- Not for the same protocol and IP address at the same time—the OS will refuse to bind a second listener to a port that's already in use (a 'port already in use' error). However, a TCP service and a UDP service can share the same port number, since they are tracked independently.