TCP and UDP Port Reference for Developers

When you read a firewall log, docker-compose file, or netstat output, the first question is often simple: what service uses that port? The Port Reference tool answers that with a searchable table of common TCP and UDP assignments — no network scanning, no account, no API calls.

What you can search

• Port number — e.g. 443, 27017
• Service name — e.g. postgres, kafka, smtp
• Category — Web, Database, Mail, DNS, Remote Access, Security, Messaging, DevOps, Monitoring, and more
• Protocol — TCP, UDP, or both

Each row includes an IANA status badge:

Status	Meaning
Well-known	Ports 0–1023 with long-standing IANA assignments (HTTP 80, SSH 22)
Registered	Official IANA assignments in the user port range (Redis 6379, Kafka 9092)

Common lookups

Port	Service	Typical use
80 / 443	HTTP / HTTPS	Web traffic
22	SSH	Secure shell and SFTP
53	DNS	Name resolution
3306	MySQL	Relational database
5432	PostgreSQL	Relational database
6379	Redis	Cache and pub/sub
9092	Kafka	Event streaming
6443	Kubernetes API	Cluster control plane

Port Reference vs port scanning

Port Reference is a static knowledge base — it tells you what a port usually means. A port scanner probes a live host to see what is actually listening. Use the reference when writing docs or rules; use a scanner when verifying connectivity.

Tips for firewall and compose files

1. Search the service name before opening a port publicly.
2. Prefer well-known assignments when choosing defaults for new services.
3. Document alternate ports (8080, 8443, 5433) in runbooks — defaults are not universal.

Open the Port Reference tool to search the full list and filter by category.