Port Numbers Reference

A reference of common TCP and UDP port numbers (web and email, remote access, databases, and network services) so you can recognise what runs where.

TCP and UDP ports identify which service a network connection is for. Ports 0–1023 are the well-known ports reserved for standard services; 1024–49151 are registered, and 49152–65535 are dynamic/ephemeral. Below are the ports you will meet most.

Web & email

PortProtoServiceUse
80TCPHTTPUnencrypted web traffic.
443TCPHTTPSEncrypted web traffic (TLS).
8080TCPHTTP altCommon dev / proxy web port.
25TCPSMTPSending mail between servers.
465TCPSMTPSSMTP over implicit TLS.
587TCPSMTP submissionMail submission from clients.
110TCPPOP3Retrieving mail (older).
143TCPIMAPRetrieving mail (sync).
993TCPIMAPSIMAP over TLS.

Remote access & transfer

PortProtoServiceUse
22TCPSSH / SFTPSecure shell and file transfer.
23TCPTelnetUnencrypted remote login (legacy).
21TCPFTPFile transfer control channel.
3389TCPRDPWindows Remote Desktop.
5900TCPVNCRemote desktop sharing.

Databases

PortProtoServiceUse
3306TCPMySQL / MariaDBDefault MySQL port.
5432TCPPostgreSQLDefault Postgres port.
6379TCPRedisIn-memory data store.
27017TCPMongoDBDefault MongoDB port.
1433TCPSQL ServerMicrosoft SQL Server.
9200TCPElasticsearchSearch / analytics HTTP API.

Network services

PortProtoServiceUse
53UDP/TCPDNSDomain name resolution.
67UDPDHCP serverAssigns IP addresses.
68UDPDHCP clientReceives IP configuration.
123UDPNTPNetwork time synchronization.
161UDPSNMPNetwork device monitoring.
389TCPLDAPDirectory services.
636TCPLDAPSLDAP over TLS.

On Unix, see the full mapping in /etc/services. Binding to a port below 1024 typically requires root/administrator privileges, which is why dev servers default to higher ports like 3000, 5173, or 8080.

What this does

A port numbers reference lists common TCP and UDP ports — web and email, remote access, databases, and network services — so you know what runs where.

How to use it

  1. Find a service or port number.
  2. Check its protocol.
  3. Read what it is used for.
  4. Copy the value with one tap.

Example

Port 443 carries HTTPS, the secure web protocol.

Sources & methodology

Last updated .

Frequently asked questions

What are well-known ports?

Ports 0–1023 are the well-known ports reserved for standard services like HTTP (80) and SSH (22). 1024–49151 are registered, and the rest are dynamic/ephemeral.

What’s the difference between TCP and UDP?

TCP is connection-based and reliable, used by most services. UDP is connectionless and faster but does not guarantee delivery, used by DNS, NTP, and streaming.

Why do dev servers use ports like 3000 or 8080?

Binding to ports below 1024 usually requires administrator privileges, so development tools default to higher, unprivileged ports.