Port Number Lookup
Type a port such as 3389, a range such as 8000-8100, or a name such as postgres or kerberos to see which services use it. Each entry says whether the use is the IANA assignment or just common practice, and any port from 0 to 65535 is classed as well-known, registered or dynamic. The reference is built into the page, so searches never leave your browser.
| Port | Protocol | Service | Description | Notes |
|---|
How to use
- Type a port number (443), a range (8000-8100) or a service name or keyword (ssh, postgres, kerberos). Results update as you type.
- To narrow a number to one protocol, pick TCP or UDP, or type it as 53/udp.
- Click a category chip, such as Database or Remote access, to list only those ports; with an empty search box it lists the whole category.
- Read the Notes column: IANA or De facto shows where the use comes from, and badges flag insecure, cleartext and often-blocked ports.
- For a single number, the line above the results gives its IANA range (well-known, registered or dynamic), even if no service is listed.
Examples
https — TCP for HTTPS, UDP for HTTP/3 (QUIC). Well-known port.
Four entries: 8000 (common alternative HTTP), 8009 (AJP), 8080 (http-alt) and 8086 (InfluxDB).
88 kerberos, 464 kpasswd and 749 kerberos-adm.
Dynamic / private (ephemeral) port, range 49152–65535. No service is assigned; the only match is Linux's default ephemeral range, 32768–60999.
Supported formats
- Input: one port (0–65535), a range written 8000-8100, 8000..8100 or 8000 to 8100, a port with protocol such as 53/udp, or one or more words matched against service names and descriptions.
- About 200 entries: the IANA well-known ports in everyday use plus widely used registered and unofficial ports for databases, message brokers, Docker and Kubernetes, monitoring, remote access, VoIP and games.
Privacy
This tool runs entirely in your browser. Nothing you enter or open is sent anywhere. Privacy policy.
Limitations
- This is a curated list of common ports, not the full IANA registry of more than 6,000 assignments. A port with no entry may still be assigned or in use.
- A port number only tells you what usually listens there. Any program can use any port, so check the running process (netstat, ss or lsof) before assuming what a service is.
- The Protocol column shows the transport the service normally uses. IANA often reserves both TCP and UDP for a port even when only one is used.
- De facto defaults change between product versions and can be reconfigured; check the product's own documentation for firewall rules.
FAQ
What is the difference between well-known, registered and dynamic ports?
IANA splits the 65,536 port numbers into three ranges. Ports 0–1023 are well-known (system) ports, which usually need administrator rights to listen on. Ports 1024–49151 are registered (user) ports that IANA assigns to applications on request. Ports 49152–65535 are dynamic or private ports, which are never assigned and are used for temporary client connections.
What does De facto mean in the results?
The port is widely used for that service, but it is not the service IANA assigned the port to. Kubernetes' API server on 6443 and Elasticsearch on 9200 are examples. The description gives the IANA name where it differs.
Do TCP 53 and UDP 53 count as the same port?
No. TCP and UDP have separate port spaces, so a firewall rule for TCP 53 does not open UDP 53. DNS uses both: UDP for most queries and TCP for large answers and zone transfers.
Does this tool scan my network or check if a port is open?
No. It is a reference only and makes no network connections. To test whether a port is reachable, use a tool such as nc, Test-NetConnection or nmap on a network you are allowed to scan.