Random Port Generator: One Port From 1024 to 49151: how it works
This random port generator draws one number from 1024 to 49151, the range that IANA registers to applications. Skip what is on the list is switched on, so the 124 numbers held by the 56 listed services in that range, from 3306 for MySQL to the 64 ports of X11, never come up. Switch it off and a listed port shows its entry under the result.
The three port ranges in RFC 6335
A port is a 16-bit number, so there are 65,536. System ports, 0 to 1023, hold the oldest services, and by default Linux lets only root, or a program given that right, open one. User ports, 1024 to 49151, are 48,128 numbers that IANA registers to applications; about 12 in 100 are taken. Dynamic ports, 49152 to 65535, are never assigned.
Worked example: the draw gives 41,852
The line under the result says it is not on the list, and the IANA registry shows it as unassigned. But Linux lends ports 32768 to 60999 to outgoing connections by default, so another program may hold 41852 for a moment. For a server that must start every time, tap 1024 to 32767 and draw again. Copy gives plain digits.
Tips
Most everyday defaults sit below 10000. Tap 10001 to 32767 to stay clear of them and of the Linux range. Only three listed ports sit higher: 11211, 15672 and 27017.
Need a block? Set How many to 3 and Order to Lowest first: app, admin page, metrics. No repeats is already on.
A random port avoids clashes. It does not hide a service: a port scan can try all 65,536.
Questions and answers
Can the draw return a port that is already in use?
Yes. The skip only knows the list, and the draw cannot see your machine. On Linux, ss -ltn lists every listening TCP port, and on macOS netstat -an does. lsof -i :41852 names the program that holds a port, but without sudo it sees only your own programs. On Windows, netstat -ano lists every port in use with its process ID.
Should I pick a registered port or a dynamic one?
For a service that other programs connect to, draw from the registered range. IANA never assigns a dynamic port, 49152 to 65535, so no product claims one, but Windows and FreeBSD lend those ports to outgoing connections, so one may be taken when your server starts.
Is port 8080 official?
Yes: IANA registers 8080 as http-alt, an alternate to port 80. In the registry 3000 belongs to hbci and remoteware-cl, 5000 to commplex-main and 9000 to cslistener, while 5173 and 9229 are unassigned. Dev tools open all five by habit, and the list marks 19 such entries.
110 POP3Post Office Protocol version 3: a mail app downloads messages from the server.
123 NTPNetwork Time Protocol keeps computer clocks in step.
143 IMAPInternet Message Access Protocol: mail stays on the server and syncs to each device.
161 and 162 SNMPNetwork monitoring: queries go to 161 and alerts, called traps, arrive on 162.
179 BGPBorder Gateway Protocol: the routers of separate networks swap routes here.
20 and 21 FTPFile Transfer Protocol: 21 carries the commands and 20 carries the files.
22 SSHSecure Shell: remote logins and file copies over an encrypted link.
23 TelnetA plain-text remote terminal. SSH on port 22 does the same job with encryption.
25 SMTPSimple Mail Transfer Protocol: mail servers pass messages to each other here.
389 LDAPLightweight Directory Access Protocol. Port 636 is the version over TLS.
443 HTTPSHTTP over TLS: the default port for secure web pages.
445 SMB file sharingSMB file sharing on Windows networks. The registry calls it microsoft-ds.
465 mail submission over TLSA mail app hands outgoing mail to its server with TLS from the first byte (RFC 8314).
514 syslogSystem log messages over UDP. On TCP the same number belongs to the old remote shell.
53 DNSDomain name lookups, registered for both UDP and TCP.
587 mail submissionOutgoing mail from an app to its server, as set out in RFC 6409.
631 IPPInternet Printing Protocol, for sending print jobs across a network.
67 and 68 DHCPHow a device gets its IP address: servers listen on 67 and clients on 68.
80 HTTPThe default port for web pages sent without encryption.
853 DNS over TLSEncrypted DNS lookups, defined in RFC 7858.
88 KerberosKerberos sign-in tickets, defined in RFC 4120.
993 IMAP over TLSThe encrypted version of IMAP on port 143.
995 POP3 over TLSThe encrypted version of POP3 on port 110.
Databases and caches 10
11211 memcachedThe memcached memory cache, registered under the name memcache.
1433 Microsoft SQL ServerThe default listener of Microsoft SQL Server, registered as ms-sql-s.
1521 Oracle database listenerOracle's default listener by habit. The registry gives 1521 to nCube License Manager.
27017 MongoDBThe mongod and mongos processes, registered for TCP only as mongodb.
3306 MySQLThe registered default port of a MySQL server.
5432 PostgreSQLThe registered default port of a PostgreSQL server.
5984 CouchDBRegistered to the CouchDB database server.
6379 RedisRedis, registered for TCP only as a key-value cache and store.
9042 Cassandra clientsApache Cassandra's native client protocol by habit. The registry lists 9042 as unassigned.
9200 ElasticsearchThe default Elasticsearch port by habit. The registry gives 9200 to a WAP session service.
Web servers and dev tools 15
3000 dev serversRuby on Rails, Create React App and Grafana open here by habit. The registry lists hbci and remoteware-cl.
3128 Squid proxyThe Squid caching web proxy by habit. The registry lists it as ndl-aas.
3690 SubversionRegistered to the Subversion version control system as svn.
4200 Angular dev serverAngular apps by habit. The registry gives 4200 to 4299 to VRML multi-user systems.
5000 Flask and ASP.NET CoreFlask and ASP.NET Core dev servers and Apple's AirPlay receiver. Registered as commplex-main.
5173 Vite dev serverThe Vite dev server by habit. The registry lists 5173 as unassigned.
8000 Django and Python http.serverDjango's dev server and Python 3 http.server by habit. The registry lists it as irdmi.
8008 HTTP alternateRegistered as an alternate port for HTTP, like 8080.
8080 HTTP alternateThe registered alternate to port 80, and the port Apache Tomcat opens on.
8123 Home Assistant and ClickHouseHome Assistant and the ClickHouse HTTP interface by habit. Unassigned in the registry.
8443 HTTPS by habitApache Tomcat's TLS port by habit. The registry lists 8443 as pcsync-https.
8888 Jupyter notebooksJupyter notebook dashboards by habit. The registry gives 8888 to a NewsEDGE server.
9000 PHP-FPM and SonarQubePHP-FPM, SonarQube and ClickHouse's native interface by habit. Registered as cslistener.
9229 Node.js debuggerThe Node.js debugger listens here by habit. The registry lists 9229 as unassigned.
9418 GitThe git:// protocol, registered as the git pack transfer service.
Queues, containers and monitoring 14
15672 RabbitMQ managementThe RabbitMQ management plugin by habit. The registry lists 15672 as unassigned.
1883 MQTTMessage Queuing Telemetry Transport, a publish and subscribe protocol for small devices.
2375 and 2376 Docker APIThe Docker REST API: 2375 in plain text and 2376 over TLS.
2379 and 2380 etcdThe etcd key-value store: 2379 for clients and 2380 between servers.
4369 Erlang port mapperepmd, the Erlang Port Mapper Daemon, which tells Erlang nodes where to find each other.
5222 XMPP clientsChat clients connect to an XMPP server here (RFC 6120).
5269 XMPP serversXMPP servers pass messages to each other here (RFC 6120).
5601 KibanaThe Kibana dashboard by habit. The registry lists it as esmagent.
5672 AMQPAdvanced Message Queuing Protocol, registered for TCP, UDP and SCTP.
6443 Kubernetes API serverThe Kubernetes API server by habit. The registry lists it as sun-sr-https.
6514 syslog over TLSEncrypted system log messages, defined in RFC 5425.
8883 MQTT over TLSThe encrypted version of MQTT on port 1883, registered as secure-mqtt.
9090 PrometheusThe Prometheus metrics server and the Cockpit admin page by habit. Registered as websm.
9092 Kafka brokersApache Kafka by habit. The registry lists 9092 as XmlIpcRegSvc.
Remote access, VPN and network 17
10000 NDMP and WebminRegistered for network backups (NDMP). The Webmin admin panel defaults here too.
1080 SOCKS proxyThe registered port of the SOCKS proxy protocol.
1194 OpenVPNRegistered to OpenVPN for both TCP and UDP.
1701 L2TPLayer 2 Tunneling Protocol. The older l2f service shares the number in the registry.
1723 PPTPPoint-to-Point Tunneling Protocol, a VPN method set out in RFC 2637.
1812 and 1813 RADIUSNetwork sign-in checks on 1812 (RFC 2865) and usage accounting on 1813 (RFC 2866).
1900 SSDPSimple Service Discovery Protocol: how UPnP devices find each other on a network.
2049 NFSNetwork File System, for mounting folders that live on another machine.
3260 iSCSIDisk storage carried over a network, defined in RFC 7143.
3389 Remote DesktopWindows Remote Desktop (RDP). The registry calls it ms-wbt-server.
3478 STUN and TURNHelps calls find a path through NAT routers (RFC 8489 and RFC 8656).
5060 and 5061 SIPSession Initiation Protocol for internet phone calls: 5060 plain and 5061 over TLS.
5353 Multicast DNSFinds devices by name on a local network without a DNS server (RFC 6762).
5900 VNCRemote Framebuffer, the protocol under VNC screen sharing (RFC 6143).
5985 and 5986 WinRMWindows Remote Management: 5985 over HTTP and 5986 over HTTPS.
6000 to 6063 X11The X Window System holds this whole block of 64 ports.
6697 IRC over TLSInternet Relay Chat with encryption, set out in RFC 7194.
How this list was compiled: 79 port numbers (or short blocks) that a developer is likely to meet, written for this site and checked 2026-09-18. Port 3000 was read again on 2026-09-19: the registry has rows for hbci and for remoteware-cl, the second with a note that the entry records an unassigned but widespread use. Every service name, RFC number and 'unassigned' or 'TCP only' note was matched by script against the IANA Service Name and Transport Protocol Port Number Registry, last updated 2026-09-11: https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml (the CSV at https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv). The three ranges (system ports 0 to 1023, user ports 1024 to 49151, dynamic ports 49152 to 65535, never assigned) are from RFC 6335 section 6: https://www.rfc-editor.org/rfc/rfc6335 and the note at the head of the registry. Uses marked 'by habit' are not IANA assignments; each was matched by script against the row for that port in https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers (wikitext fetched 2026-09-18), and a use that the article tags 'citation needed' was left out. Product names are plain-text references and belong to their owners. IANA's own note applies: an assignment does not endorse a product, and traffic on a registered port is not proof of the assigned service. Licence: own work