🔌 Port Number Reference
Search and browse common TCP/UDP port numbers and their services
Showing 51 of 51 ports
| Port | Protocol | Service | Description | |
|---|---|---|---|---|
| 20 | TCP | FTP Data | File Transfer Protocol – data transfer channel | |
| 21 | TCP | FTP Control | File Transfer Protocol – command/control channel | |
| 22 | TCP | SSH | Secure Shell – encrypted remote login and command execution | |
| 23 | TCP | Telnet | Unencrypted remote terminal access (deprecated) | |
| 25 | TCP | SMTP | Simple Mail Transfer Protocol – email sending | |
| 53 | TCP/UDP | DNS | Domain Name System – resolves domain names to IP addresses | |
| 67 | UDP | DHCP Server | Dynamic Host Configuration Protocol – assigns IP addresses to clients | |
| 68 | UDP | DHCP Client | Dynamic Host Configuration Protocol – client side | |
| 69 | UDP | TFTP | Trivial File Transfer Protocol – simplified file transfers | |
| 80 | TCP | HTTP | HyperText Transfer Protocol – standard unencrypted web traffic | |
| 110 | TCP | POP3 | Post Office Protocol v3 – retrieves email from a server | |
| 119 | TCP | NNTP | Network News Transfer Protocol – Usenet newsgroups | |
| 123 | UDP | NTP | Network Time Protocol – clock synchronization between devices | |
| 143 | TCP | IMAP | Internet Message Access Protocol – retrieves and manages email | |
| 161 | UDP | SNMP | Simple Network Management Protocol – network device monitoring | |
| 162 | UDP | SNMP Trap | SNMP trap notifications from managed devices | |
| 179 | TCP | BGP | Border Gateway Protocol – inter-domain routing protocol | |
| 194 | TCP | IRC | Internet Relay Chat – real-time messaging protocol | |
| 389 | TCP/UDP | LDAP | Lightweight Directory Access Protocol – directory services | |
| 443 | TCP | HTTPS | HTTP Secure – encrypted web traffic via TLS/SSL | |
| 445 | TCP | SMB | Server Message Block – Windows file sharing and network resources | |
| 465 | TCP | SMTPS | SMTP over TLS – encrypted email submission (legacy) | |
| 514 | UDP | Syslog | System logging protocol – sends log messages over a network | |
| 587 | TCP | SMTP Submission | Email submission port with STARTTLS – modern email sending | |
| 636 | TCP | LDAPS | LDAP over SSL/TLS – secure directory access | |
| 993 | TCP | IMAPS | IMAP over SSL/TLS – secure email retrieval | |
| 995 | TCP | POP3S | POP3 over SSL/TLS – secure email retrieval | |
| 1080 | TCP | SOCKS | SOCKS proxy protocol – network proxy for TCP connections | |
| 1194 | UDP | OpenVPN | OpenVPN – open-source VPN tunneling protocol | |
| 1433 | TCP | MSSQL | Microsoft SQL Server database engine | |
| 1521 | TCP | Oracle DB | Oracle Database listener | |
| 1723 | TCP | PPTP | Point-to-Point Tunneling Protocol – VPN | |
| 2049 | TCP/UDP | NFS | Network File System – remote file sharing | |
| 2181 | TCP | ZooKeeper | Apache ZooKeeper – distributed coordination service | |
| 2375 | TCP | Docker | Docker REST API (unencrypted) – container management | |
| 2376 | TCP | Docker TLS | Docker REST API over TLS – secure container management | |
| 3000 | TCP | Dev Server | Common development server port (Node.js, React, etc.) | |
| 3306 | TCP | MySQL | MySQL database server | |
| 3389 | TCP/UDP | RDP | Remote Desktop Protocol – Windows remote desktop access | |
| 4443 | TCP | HTTPS Alt | Alternate HTTPS port used by some web servers | |
| 5000 | TCP | Flask / UPnP | Common Flask development server; also UPnP | |
| 5432 | TCP | PostgreSQL | PostgreSQL database server | |
| 5900 | TCP | VNC | Virtual Network Computing – remote desktop | |
| 6379 | TCP | Redis | Redis in-memory data store | |
| 6443 | TCP | Kubernetes API | Kubernetes API server | |
| 8080 | TCP | HTTP Alt | Alternate HTTP port – common for development and proxies | |
| 8443 | TCP | HTTPS Alt | Alternate HTTPS port – common for development servers | |
| 8888 | TCP | Jupyter | Jupyter Notebook web interface | |
| 9200 | TCP | Elasticsearch | Elasticsearch REST API | |
| 9300 | TCP | Elasticsearch | Elasticsearch inter-node communication | |
| 27017 | TCP | MongoDB | MongoDB document database server |
About Port Number Reference
Port numbers are how computers distinguish between multiple network services running on the same IP address. Every time you open a website, connect to a database, or send an email, your OS uses port numbers to route that traffic to the right application. This reference covers the most commonly used TCP and UDP ports across web, email, databases, remote access, and development.
Ports are managed by IANA (Internet Assigned Numbers Authority) and divided into three ranges: well-known ports (0–1023) for standard services, registered ports (1024–49151) for application-specific services, and dynamic/ephemeral ports (49152–65535) for temporary client connections.
How to Use Port Number Reference
Search — Type a port number (e.g., 3306), service name (e.g., mysql), or keyword in the search box to instantly filter results.
Filter by Protocol — Select TCP or UDP to narrow results to a specific transport protocol.
Filter by Category — Choose between well-known (0–1023), registered (1024–49151), or dynamic port ranges.
Copy Port — Click the copy icon on any row to copy the port number to your clipboard.
Port Number FAQ
What is a port number?
A port number is a 16-bit integer (0–65535) used by network protocols to identify specific processes or services on a device. It works alongside an IP address to direct traffic to the correct application.
What are well-known ports?
Well-known ports range from 0 to 1023 and are reserved for common services like HTTP (80), HTTPS (443), SSH (22), and FTP (21). They are assigned by IANA and require administrator privileges to use.
What is the difference between TCP and UDP ports?
TCP (Transmission Control Protocol) ports provide reliable, ordered, and error-checked communication — used for web, email, and file transfer. UDP (User Datagram Protocol) ports are faster but connectionless — used for DNS, streaming, and gaming where speed matters more than reliability.
What are registered ports?
Registered ports (1024–49151) are assigned by IANA to specific applications and services. Examples include MySQL (3306), PostgreSQL (5432), and RDP (3389). They don't require root/admin privileges.
What are dynamic or ephemeral ports?
Dynamic ports (49152–65535) are used temporarily by client applications for outgoing connections. The OS assigns these automatically and they're released when the connection closes.
How do I check which ports are open on my system?
On Linux/Mac use `netstat -tuln` or `ss -tuln`. On Windows use `netstat -an`. You can also use tools like nmap for scanning remote hosts.
Pro Tips
- • Ports below 1024 require root/administrator privileges to bind on Linux and macOS.
- • Always close or firewall unused ports to reduce your attack surface.
- • Use port 587 with STARTTLS (not port 25) for outgoing email from applications.
- • Docker exposes internal container ports via host port mapping — check your -p flags.
- • Port 8080 and 8443 are common alternatives when 80/443 are already in use.
- • Use `lsof -i :PORT` on Mac/Linux to find which process is using a specific port.