Port Reference

Complete reference of well-known TCP/UDP port numbers - databases, web servers, email, security, and more.

PortServiceProtocolDescription

20FTP DataTCPFile Transfer Protocol - data transfer

21FTP ControlTCPFile Transfer Protocol - control commands

22SSHTCPSecure Shell - encrypted remote access

23TelnetTCPUnencrypted remote shell (deprecated)

25SMTPTCPSimple Mail Transfer Protocol - outgoing email

53DNSTCP/UDPDomain Name System - hostname resolution

67DHCP ServerUDPDynamic Host Configuration Protocol

68DHCP ClientUDPDHCP client port

80HTTPTCPHypertext Transfer Protocol - web traffic

110POP3TCPPost Office Protocol - incoming email

143IMAPTCPInternet Message Access Protocol - email

194IRCTCPInternet Relay Chat

389LDAPTCPLightweight Directory Access Protocol

443HTTPSTCPHTTP over TLS/SSL - secure web traffic

445SMBTCPServer Message Block - Windows file sharing

465SMTPSTCPSMTP over SSL - secure outgoing email

500IKE / IPsecUDPInternet Key Exchange - VPN negotiation

587SMTP (TLS)TCPEmail submission with STARTTLS

993IMAPSTCPIMAP over SSL - secure email

995POP3STCPPOP3 over SSL - secure email

1194OpenVPNTCP/UDPOpenVPN default port

1433MSSQLTCPMicrosoft SQL Server database

1521Oracle DBTCPOracle Database default listener

1723PPTPTCPPoint-to-Point Tunneling Protocol (VPN)

2049NFSTCP/UDPNetwork File System

2181ZooKeeperTCPApache ZooKeeper client connections

3000Dev ServerTCPCommon Node.js / React development server

3306MySQLTCPMySQL / MariaDB database

3389RDPTCPRemote Desktop Protocol - Windows remote access

4443Alt HTTPSTCPAlternate HTTPS port

5000Dev / FlaskTCPCommon Flask / Python dev server port

5432PostgreSQLTCPPostgreSQL database

5672RabbitMQTCPRabbitMQ AMQP message broker

5900VNCTCPVirtual Network Computing - remote desktop

6379RedisTCPRedis in-memory data store

6443Kubernetes APITCPKubernetes API server

8000Alt HTTPTCPCommon alternate HTTP / Django dev port

8080Alt HTTPTCPCommon alternate HTTP / proxy port

8443Alt HTTPSTCPCommon alternate HTTPS port

8888JupyterTCPJupyter Notebook default port

9000PHP-FPMTCPPHP FastCGI Process Manager

9090PrometheusTCPPrometheus metrics server

9092KafkaTCPApache Kafka broker

9200ElasticsearchTCPElasticsearch HTTP API

27017MongoDBTCPMongoDB database

11211MemcachedTCP/UDPMemcached in-memory cache

46 of 46 ports shown

About this tool

A searchable reference of 46 well-known TCP and UDP port numbers, covering databases, web servers, email protocols, security services, and developer tools. Filter by category (Web, Database, Email, Security, Dev) or search by port number, service name, or description. Useful for configuring firewalls, debugging connection issues, and learning network fundamentals.

How to Use the Port Reference

1Browse all 46 ports in the table, or use the search box to find a specific port.
2Filter by category: Web, Database, Email, Security, or Dev to narrow the list.
3Click any column header concept to understand protocol (TCP vs UDP) differences.
4Use the port number or service name to configure firewall rules or debug connection issues.

Frequently Asked Questions

What is a port number?+

A port number is a 16-bit number (0–65535) that identifies a specific process or service on a networked device. Port 80 is HTTP, 443 is HTTPS, 22 is SSH, and so on.

What is the difference between TCP and UDP?+

TCP (Transmission Control Protocol) guarantees delivery and order - used for HTTP, SSH, databases. UDP (User Datagram Protocol) is faster but doesn't guarantee delivery - used for DNS, streaming, VPNs.

Which ports should I keep closed on a server?+

Close any ports you don't actively use. Common security risks: Telnet (23), FTP (21), RDP (3389) exposed to the internet. Use SSH (22) with key-based auth, and consider non-standard ports for SSH.

How do I check if a port is open on my server?+

Use nmap (nmap -p PORT host), netcat (nc -zv host PORT), or telnet (telnet host PORT). For a web-based check, tools like portchecker.co can test external reachability.

Looking for a deeper guide on this topic? Browse the Searchlight blog.

Visit the blog →

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