Port Numbers
Well-known and registered TCP and UDP ports and the services behind them.
About Port Numbers
A port numbers list of well-known and registered TCP and UDP ports developers meet: web, mail, DNS, SSH, databases, brokers, dev servers, Kubernetes and VPNs.
How to use
- Type a port number (
5432), a service name (postgres) or a word from the description (metrics). - Use the range switch to show only system ports (0–1023), registered ports (1024–49151) or dynamic ports (49152–65535).
- Copy copies the port number.
What is covered
| Group | Examples |
|---|---|
| Core internet and system | 20/21 FTP, 22 SSH, 25 SMTP, 53 DNS, 67/68 DHCP, 80 HTTP, 123 NTP, 143 IMAP, 389 LDAP, 443 HTTPS, 445 SMB, 587 submission, 993 IMAPS |
| Databases | 1433 SQL Server, 1521 Oracle, 3306 MySQL, 5432 PostgreSQL, 6379 Redis, 7687 Neo4j, 9042 Cassandra, 9200 Elasticsearch, 27017 MongoDB |
| Message brokers | 1883 MQTT, 2181 ZooKeeper, 4222 NATS, 5672 AMQP, 9092 Kafka |
| Development servers | 3000, 4200, 5000, 5173, 8000, 8080, 8443, 8888 |
| Containers and observability | 2375/2376 Docker, 2379 etcd, 6443 Kubernetes API, 10250 kubelet, 8200 Vault, 8500 Consul, 9090 Prometheus, 3100 Loki |
| Remote access and VPN | 1194 OpenVPN, 3389 RDP, 5900 VNC, 500/4500 IPsec, 51820 WireGuard |
- The protocol column says whether the service runs over TCP, UDP or both. HTTPS is listed as both because HTTP/3 uses QUIC over UDP 443.
- IANA splits the range: system (well-known) ports 0–1023 need root to bind on Unix, registered ports 1024–49151 are assigned to services on request, and dynamic or private ports 49152–65535 are for ephemeral client connections and are never assigned.
- Development defaults such as 3000, 5173 and 8000 are conventions, not assignments. Several tools share a port and the description names the common ones.
Example
Filter: mail
→ 25 TCP SMTP Mail transfer between servers
→ 465 TCP SMTPS Mail submission over implicit TLS
→ 587 TCP SMTP submission Mail submission from clients, with STARTTLS
Privacy
The list is part of the page. Filtering runs in the browser; no request is made and nothing is stored.
Frequently asked questions
- What port does HTTPS use?
- TCP port 443. HTTP/3 also uses 443 but over UDP, because QUIC runs on UDP. Plain HTTP uses TCP 80, and 8443 is the usual alternative when a server cannot bind 443.
- What is the difference between well-known and registered ports?
- Well-known (system) ports are 0 to 1023 and on Unix only root can listen on them; they hold the core protocols such as SSH, DNS and HTTP. Registered ports, 1024 to 49151, are assigned by IANA to applications on request, such as 3306 for MySQL. Ports above 49151 are dynamic and never assigned.
- What port does SMTP use?
- Port 25 for server-to-server mail transfer, 587 for clients submitting mail with STARTTLS, and 465 for submission over implicit TLS. Mail clients should use 587 or 465; many ISPs and cloud providers block outbound 25.
- Which ports do Kubernetes components use?
- The API server listens on 6443, etcd on 2379 for clients and 2380 for peers, the kubelet on 10250 on every node, kube-scheduler on 10259 and kube-controller-manager on 10257. NodePort services use 30000 to 32767 by default.