What is the difference between TCP and UDP ports?

TCP is connection-oriented and guarantees ordered, reliable delivery, which suits web pages, email and databases. UDP is connectionless and faster but without delivery guarantees, which suits DNS lookups, time sync and streaming. Some services such as DNS use both.

What are well-known ports?

Well-known ports are the numbers from 0 to 1023 reserved by IANA for common services such as HTTP on 80 and HTTPS on 443. Ports 1024 to 49151 are registered ports, and 49152 to 65535 are dynamic or ephemeral ports used for temporary client connections.

What port does HTTPS use?

HTTPS uses TCP port 443, and plain HTTP uses port 80. Browsers default to these, which is why you rarely type a port in a normal web address.

What are the default database ports?

MySQL listens on 3306, PostgreSQL on 5432, Redis on 6379, MongoDB on 27017 and Microsoft SQL Server on 1433. These defaults are useful when configuring connections or firewall rules.

Which ports does email use?

SMTP submission uses 587 (or 25 for server-to-server), IMAP over TLS uses 993, and POP3 over TLS uses 995. Secure submission and retrieval prefer the TLS ports.

SSH uses TCP port 22 by default, and RDP (Windows remote desktop) uses 3389. Administrators sometimes move SSH to a non-standard port to reduce automated scanning.

Is anything I search sent to a server?

No. The full port list and the search both run entirely in your browser — nothing you type is uploaded anywhere.

What is the Port Numbers Reference?

A searchable reference of well-known network ports — 22 SSH, 80 HTTP, 443 HTTPS, 3306 MySQL, 5432 PostgreSQL and more — grouped by purpose with a plain-English description. Runs entirely in your browser, nothing is uploaded. It runs free in your browser on Gera Tools, with nothing uploaded.

Port Numbers Reference

Name: Port Numbers Reference
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Get one useful tool a week

Like this tool? Enter your email and we'll send you one genuinely useful Gera tool a week — plus a link to come back to this one. No spam, one-click unsubscribe any time.

Network ports — searchable reference

A grouped, searchable list of the network ports developers and sysadmins actually run into — for configuring servers, opening firewall rules, or debugging a connection. Each entry shows the port number, protocol (TCP or UDP), the service, and a plain-English description.

How it works

Ports are organised into groups — web, email, remote access, databases, networking and messaging — and the search box filters the whole list by number, service name or keyword instantly. Port numbers fall into three IANA ranges:

0–1023 — well-known ports (HTTP 80, HTTPS 443, SSH 22)
1024–49151 — registered ports (databases, app servers)
49152–65535 — dynamic / ephemeral ports for temporary client connections

Common ports quick reference

Port	Protocol	Service	Notes
22	TCP	SSH	Default; often moved to a high port to reduce scanning
25	TCP	SMTP (relay)	Server-to-server only; blocked by most ISPs for clients
53	TCP/UDP	DNS	TCP for zone transfers; UDP for queries
80	TCP	HTTP	Browsers redirect to HTTPS 443 when HSTS is set
443	TCP	HTTPS	TLS-wrapped HTTP; also used for QUIC/HTTP3 over UDP
587	TCP	SMTP (submission)	Client-to-server with STARTTLS; preferred over 465
993	TCP	IMAP over TLS	Secure inbox retrieval; implicit TLS
995	TCP	POP3 over TLS	Secure mail download; implicit TLS
3306	TCP	MySQL	Also used by MariaDB
5432	TCP	PostgreSQL	Default; widely firewalled in cloud environments
6379	TCP	Redis	No auth by default; must be firewalled or bound to localhost
27017	TCP	MongoDB	Default; Atlas uses TLS on the same port
3389	TCP	RDP	Windows Remote Desktop; common brute-force target
8080	TCP	HTTP alt	Frequently used for dev servers and HTTP proxies
8443	TCP	HTTPS alt	HTTPS alternative for non-root dev servers

TCP vs UDP: when it matters

TCP establishes a connection before sending data, guarantees ordered delivery, and retransmits lost packets. This makes it the right choice for web, email, databases, and remote shells — anywhere correctness and order matter. UDP sends packets without a handshake, with no delivery guarantee, which makes it faster and lower-overhead for services that can tolerate some loss: DNS queries, time synchronisation (NTP on 123), and media streaming. Some services such as DNS use both — UDP for normal queries and TCP for responses over 512 bytes or zone transfers.

Firewall rule tips

When opening firewall rules, the minimal-access principle is: allow only the specific port and protocol the service actually uses, and restrict the source IP range if possible. Redis (6379), PostgreSQL (5432), and MySQL (3306) should never be reachable from the public internet — bind them to localhost or a private VLAN and expose them only to application servers that need them.

Searching 5432 in the table jumps straight to the PostgreSQL row, while typing mail surfaces SMTP, IMAP, and POP3 entries together. Everything runs in your browser; nothing is uploaded.