Port Number Reference
Look up common TCP and UDP port numbers for databases, web servers, mail, SSH and developer tools, and see which ports clash. Free reference, no sign-up.
Check a port number
| Port | Protocol | Service | What it is |
|---|---|---|---|
| 20 | TCP | FTP data | File transfer data channel. |
| 21 | TCP | FTP | File transfer control channel. |
| 22 | TCP | SSH | Secure shell, SFTP and SCP. |
| 23 | TCP | Telnet | Unencrypted remote login. Avoid. |
| 25 | TCP | SMTP | Mail delivery between servers; often blocked by home ISPs. |
| 53 | TCP/UDP | DNS | Domain name lookups. |
| 67 | UDP | DHCP server | Hands out IP addresses. |
| 68 | UDP | DHCP client | Receives IP addresses. |
| 69 | UDP | TFTP | Trivial file transfer. |
| 80 | TCP | HTTP | Unencrypted web. |
| 110 | TCP | POP3 | Mail download. |
| 119 | TCP | NNTP | Usenet news. |
| 123 | UDP | NTP | Time synchronisation. |
| 137 | UDP | NetBIOS name | Windows name service. |
| 139 | TCP | NetBIOS session | Old Windows file sharing. |
| 143 | TCP | IMAP | Mail access. |
| 161 | UDP | SNMP | Network device monitoring. |
| 162 | UDP | SNMP trap | Alerts from devices. |
| 179 | TCP | BGP | Internet routing. |
| 389 | TCP/UDP | LDAP | Directory services. |
| 443 | TCP | HTTPS | Encrypted web. |
| 445 | TCP | SMB | Windows file sharing. Do not expose to the internet. |
| 465 | TCP | SMTPS | Mail submission over TLS. |
| 500 | UDP | IKE | IPsec VPN key exchange. |
| 514 | UDP | Syslog | Log forwarding. |
| 515 | TCP | LPD | Printing. |
| 587 | TCP | SMTP submission | Mail sending from clients (STARTTLS). |
| 631 | TCP/UDP | IPP / CUPS | Network printing. |
| 636 | TCP | LDAPS | Directory services over TLS. |
| 853 | TCP | DNS over TLS | Encrypted DNS. |
| 873 | TCP | rsync | File synchronisation. |
| 993 | TCP | IMAPS | Mail access over TLS. |
| 995 | TCP | POP3S | Mail download over TLS. |
| 1080 | TCP | SOCKS proxy | Generic proxy. |
| 1194 | UDP | OpenVPN | VPN (UDP by default). |
| 1433 | TCP | Microsoft SQL Server | Database connections. |
| 1521 | TCP | Oracle Database | Database listener. |
| 1723 | TCP | PPTP | Old VPN protocol. |
| 1883 | TCP | MQTT | IoT messaging. |
| 2049 | TCP/UDP | NFS | Network file system. |
| 2181 | TCP | ZooKeeper | Coordination service client port. |
| 2375 | TCP | Docker (no TLS) | Docker daemon API. Never expose to the internet. |
| 2376 | TCP | Docker (TLS) | Docker daemon API with TLS. |
| 2379 | TCP | etcd client | Key-value store used by Kubernetes. |
| 2380 | TCP | etcd peer | Cluster traffic between etcd nodes. |
| 3000 | TCP | Dev servers | Default for React (CRA), Express examples, Rails and Grafana. Also: Grafana, Node/Express, Rails, Next.js, Create React App all use 3000 by default. |
| 3306 | TCP | MySQL / MariaDB | Database connections. |
| 3389 | TCP | RDP | Windows remote desktop. Do not expose to the internet. |
| 3478 | UDP | STUN / TURN | WebRTC connectivity. |
| 4000 | TCP | Dev servers | Phoenix, Jekyll serve and many Node tools. |
| 4200 | TCP | Angular dev server | ng serve default. |
| 4369 | TCP | Erlang port mapper | Used by RabbitMQ clustering. |
| 4443 | TCP | Alternative HTTPS | Common for admin interfaces. |
| 4500 | UDP | IPsec NAT-T | VPN through NAT. |
| 5000 | TCP | Dev servers | Flask, Docker registry and .NET examples. Also: macOS Monterey and later use 5000 for AirPlay Receiver: turn it off in System Settings if Flask will not start. |
| 5060 | TCP/UDP | SIP | Voice over IP signalling. |
| 5173 | TCP | Vite dev server | Default for Vite. |
| 5353 | UDP | mDNS | Local network name discovery (Bonjour, Avahi). |
| 5432 | TCP | PostgreSQL | Database connections. |
| 5601 | TCP | Kibana | Elasticsearch dashboards. |
| 5672 | TCP | RabbitMQ (AMQP) | Message broker. |
| 5900 | TCP | VNC | Remote desktop. Do not expose to the internet. |
| 5984 | TCP | CouchDB | Database HTTP API. |
| 6379 | TCP | Redis | Cache and data store. Never expose without a password. |
| 6443 | TCP | Kubernetes API server | Cluster control endpoint. |
| 6881 | TCP/UDP | BitTorrent | Peer file sharing. |
| 7000 | TCP | Cassandra / AirPlay | Cassandra inter-node traffic. Also: macOS AirPlay Receiver also listens on 7000. |
| 8000 | TCP | Dev servers | Django runserver, Python http.server and many tools. |
| 8008 | TCP | Alternative HTTP | Seen on Chromecast and some proxies. |
| 8080 | TCP | Alternative HTTP | Tomcat, Jenkins, proxies and many dev servers. Also: Jenkins, Tomcat, Spring Boot and many proxies all default to 8080. |
| 8081 | TCP | Alternative HTTP | Metro bundler for React Native, Nexus and others. |
| 8088 | TCP | Alternative HTTP | Hadoop YARN web UI and others. |
| 8443 | TCP | Alternative HTTPS | Tomcat TLS and admin consoles. |
| 8883 | TCP | MQTT over TLS | Encrypted IoT messaging. |
| 8888 | TCP | Jupyter Notebook | Default notebook port. |
| 9000 | TCP | Various | PHP-FPM, SonarQube, Portainer and MinIO. Also: PHP-FPM, SonarQube, Portainer, MinIO and Webpack dev servers. |
| 9042 | TCP | Cassandra CQL | Client connections. |
| 9090 | TCP | Prometheus | Metrics server web UI. Also: Also used by Cockpit and some admin consoles. |
| 9092 | TCP | Apache Kafka | Broker client connections. |
| 9100 | TCP | Node Exporter / printers | Prometheus node metrics; raw network printing. |
| 9200 | TCP | Elasticsearch HTTP | Search API. |
| 9300 | TCP | Elasticsearch transport | Node-to-node traffic. |
| 9418 | TCP | Git protocol | Anonymous git:// access. |
| 10250 | TCP | Kubelet | Node agent API. |
| 11211 | TCP/UDP | Memcached | Cache. Never expose to the internet. |
| 15672 | TCP | RabbitMQ management | Web management UI. |
| 25565 | TCP | Minecraft | Default game server. |
| 27017 | TCP | MongoDB | Database connections. |
| 27018 | TCP | MongoDB shard | Shard server. |
| 50000 | TCP | Jenkins agents / SAP | Inbound agent connections. |
| 51820 | UDP | WireGuard | Default VPN port. |
Shortcuts: Ctrl+Enter run · Ctrl+Shift+C copy result · / search (use ⌘ on Mac)
Common Port Numbers: Databases, Web, Mail and Dev Tools
Look up what a port number is normally used for, which developer tools share the same default and why a port may already be in use. It gives developers a quick browser-based way to solve a focused port number reference task before moving the result into a project.
How to use this list
Search by number or name, or filter by range. Type a port in the box below to see what it is used for and which block it belongs to.
Common mistakes
- Running two dev servers on the same default port, such as two apps on 3000, without changing one of them.
- Opening a database port to the whole internet to "make it work".
Frequently asked questions
What does "address already in use" mean?
Another program is already listening on that port. Search the number here to see what usually uses it, then stop that program or choose a different port. On Mac, AirPlay Receiver takes port 5000 and 7000.
How do I find what is using a port?
On Linux or Mac run: lsof -i :8080 . On Windows run: netstat -ano | findstr :8080 . The process id is in the last column.
What are the port ranges?
0 to 1023 are well-known system ports. 1024 to 49151 are registered for applications. 49152 to 65535 are dynamic ports used for outgoing connections.
Which ports are risky to open?
Never expose database, cache and remote-desktop ports (3306, 5432, 6379, 27017, 3389, 5900) directly to the internet. Put them behind a VPN or a firewall rule.
How do I use this port number reference tool?
Use the interactive controls above; processing stays in your browser and the result is intended as a practical starting point for development work.
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