Is the output identical to the standard library implementation?

Yes — modern browser implementations of TextEncoder, atob/btoa, crypto.subtle, and so on follow the same standards as Node.js, Python, and others.

What about very large files?

Browser memory limits files at roughly 100MB-2GB depending on browser and OS. For larger files, use a CLI tool or stream processing.

How does this compare to a CLI version?

Functionally equivalent for typical inputs. CLI versions handle larger files, batch processing, and scripting; this is faster for one-off ad-hoc use.

Does my data leave my browser?

No — everything runs in your browser’s JavaScript engine. The page makes no network calls with your input data. View Network tab in DevTools to verify.

Does it work offline?

Yes once the page is loaded. The tool runs entirely client-side; refresh while online to update, but offline use works for cached pages.

Can I use this in production?

For ad-hoc dev-team use: yes. For automated pipelines: use a versioned dependency you control. The browser tool is ideal for the human-in-the-loop step.

Developer Utilities · Free tool

Port Number Lookup

Quick reference for ~140 well-known TCP/UDP ports — search by number or service name. Web, mail, DNS, DB, SSH, Docker, Kafka, MQTT, more.

Updated May 2026

Category

90 of 90 ports

Port	Protocol	Service	Description	Category
`80`	TCP	HTTP	Plaintext web traffic. Serve only redirects to 443 in production.	Web
`443`	TCP	HTTPS	TLS-encrypted HTTP. Standard for every public web service.	Web
`8080`	TCP	HTTP-alt	Common alt-HTTP port for dev servers, Tomcat, Jenkins, proxies.	Web
`8443`	TCP	HTTPS-alt	Common alt-HTTPS port for dev / management UIs.	Web
`3000`	TCP	Dev server	Default for Node.js apps (Express, Next.js, Create React App).	Web
`3001`	TCP	Dev server (alt)	Common second Node.js port when 3000 is taken.	Web
`5000`	TCP	Flask / dev	Python Flask default. Conflicts with macOS AirPlay Receiver.	Web
`5173`	TCP	Vite	Vite dev server default.	Web
`4200`	TCP	Angular CLI	ng serve default.	Web
`8000`	TCP	Python http.server	Default for `python -m http.server`. Also Django default.	Web
`8888`	TCP	Jupyter	Jupyter Notebook / Lab default.	Web
`9000`	TCP	PHP-FPM / SonarQube	PHP-FPM listener; also default for SonarQube.	Web
`1313`	TCP	Hugo dev	Hugo static-site generator dev server.	Web
`4000`	TCP	Jekyll / Phoenix	Jekyll dev default; also Elixir Phoenix default.	Web
`25`	TCP	SMTP	Server-to-server email relay. ISPs typically block outbound to non-mail-servers.	Mail
`465`	TCP	SMTPS	SMTP over implicit TLS (legacy but still widely used).	Mail
`587`	TCP	SMTP submission	Client-to-server submission with STARTTLS. Modern outbound.	Mail
`110`	TCP	POP3	Plaintext POP3 — deprecated in favor of POP3S (995) or IMAP.	Mail
`995`	TCP	POP3S	POP3 over TLS.	Mail
`143`	TCP	IMAP	Plaintext IMAP — use IMAPS (993) instead.	Mail
`993`	TCP	IMAPS	IMAP over TLS — standard modern email retrieval.	Mail
`53`	TCP/UDP	DNS	Domain Name System queries (UDP) and zone transfers (TCP).	DNS
`853`	TCP	DNS-over-TLS	DoT — encrypted DNS. Used by 1.1.1.1, 9.9.9.9.	DNS
`5353`	UDP	mDNS	Multicast DNS / Bonjour. Powers .local hostname resolution.	DNS
`22`	TCP	SSH	Secure Shell — remote terminal, sftp, scp, port forwarding.	Auth
`88`	TCP/UDP	Kerberos	Kerberos authentication.	Auth
`389`	TCP/UDP	LDAP	Plaintext LDAP — use LDAPS (636) for production.	Auth
`636`	TCP	LDAPS	LDAP over TLS.	Auth
`464`	TCP/UDP	kpasswd	Kerberos password change.	Auth
`1812`	UDP	RADIUS	Auth requests. (Accounting on 1813.)	Auth
`1433`	TCP	MS SQL Server	Microsoft SQL Server default.	Database
`1521`	TCP	Oracle DB	Oracle Database listener default.	Database
`3306`	TCP	MySQL / MariaDB	MySQL + MariaDB default port.	Database
`5432`	TCP	PostgreSQL	Postgres default port.	Database
`6379`	TCP	Redis	Redis default — bind to localhost only unless you've configured AUTH.	Database
`9042`	TCP	Cassandra	Cassandra CQL native protocol.	Database
`9200`	TCP	Elasticsearch HTTP	Elasticsearch / OpenSearch REST API.	Database
`9300`	TCP	Elasticsearch transport	Elasticsearch internal node-to-node transport.	Database
`27017`	TCP	MongoDB	MongoDB default. Same security warning as Redis — never bind to 0.0.0.0 without auth.	Database
`5984`	TCP	CouchDB	CouchDB HTTP API.	Database
`7000`	TCP	Cassandra inter-node	Cassandra inter-node communication.	Database
`11211`	TCP/UDP	Memcached	Memcached default.	Database
`8086`	TCP	InfluxDB	InfluxDB HTTP API.	Database
`23`	TCP	Telnet	Plaintext remote shell — deprecated; use SSH instead.	Remote
`3389`	TCP	RDP	Remote Desktop Protocol — Windows. Never expose to the public internet.	Remote
`5900`	TCP	VNC	Virtual Network Computing. Like RDP but cross-platform.	Remote
`5901`	TCP	VNC display 1	Subsequent VNC displays use 5900 + display number.	Remote
`21`	TCP	FTP control	Plaintext file transfer — use SFTP (22) instead.	File transfer
`20`	TCP	FTP data	FTP active-mode data channel.	File transfer
`989`	TCP	FTPS data	FTP over implicit TLS, data channel.	File transfer
`990`	TCP	FTPS control	FTP over implicit TLS, control channel.	File transfer
`69`	UDP	TFTP	Trivial FTP — small file transfers, common in PXE boot.	File transfer
`445`	TCP	SMB	Server Message Block — Windows file sharing.	File transfer
`139`	TCP	NetBIOS	NetBIOS Session Service (legacy SMB transport).	File transfer
`2049`	TCP/UDP	NFS	Network File System.	File transfer
`5222`	TCP	XMPP client	Jabber / XMPP client connection.	Chat
`5269`	TCP	XMPP server	XMPP server-to-server.	Chat
`6667`	TCP	IRC	Internet Relay Chat (plaintext).	Chat
`6697`	TCP	IRC over TLS	Encrypted IRC.	Chat
`5060`	TCP/UDP	SIP	Session Initiation Protocol — VoIP signaling.	Chat
`5061`	TCP	SIP over TLS	Encrypted SIP.	Chat
`25565`	TCP	Minecraft Java	Minecraft Java edition default.	Game
`19132`	UDP	Minecraft Bedrock	Minecraft Bedrock edition default.	Game
`27015`	TCP/UDP	Steam / Source	Steam game server / Valve Source engine.	Game
`7777`	TCP/UDP	Unreal / Terraria	Common Unreal Engine + Terraria default.	Game
`500`	UDP	IKE / IPSec	Internet Key Exchange — IPSec VPN setup.	VPN
`4500`	UDP	IPSec NAT-T	IPSec NAT traversal.	VPN
`1194`	UDP	OpenVPN	OpenVPN default.	VPN
`1701`	UDP	L2TP	Layer 2 Tunneling Protocol.	VPN
`1723`	TCP	PPTP	Point-to-Point Tunneling — deprecated, broken cryptography.	VPN
`51820`	UDP	WireGuard	WireGuard default.	VPN
`67`	UDP	DHCP server	DHCP server-side (clients send to here).	Other
`68`	UDP	DHCP client	DHCP client-side.	Other
`123`	UDP	NTP	Network Time Protocol.	Other
`161`	UDP	SNMP	Simple Network Management Protocol — agent.	Other
`162`	UDP	SNMP trap	SNMP trap notifications.	Other
`514`	UDP	syslog	Remote system logging.	Other
`631`	TCP/UDP	IPP / CUPS	Internet Printing Protocol / CUPS daemon.	Other
`873`	TCP	rsync	rsync daemon protocol (when not over SSH).	Other
`1883`	TCP	MQTT	Message Queue Telemetry Transport — IoT.	Other
`8883`	TCP	MQTT over TLS	Encrypted MQTT.	Other
`5672`	TCP	AMQP / RabbitMQ	Advanced Message Queuing Protocol.	Other
`15672`	TCP	RabbitMQ management	RabbitMQ web management UI.	Other
`9092`	TCP	Kafka	Apache Kafka broker default.	Other
`2181`	TCP	Zookeeper	Apache ZooKeeper client.	Other
`6443`	TCP	Kubernetes API	Kubernetes API server (TLS).	Other
`2375`	TCP	Docker daemon (insecure)	Plaintext Docker API — never expose externally.	Other
`2376`	TCP	Docker daemon (TLS)	TLS-secured Docker API.	Other
`2377`	TCP	Docker Swarm	Swarm cluster management.	Other
`6379`	TCP	Sentinel	Redis Sentinel — note: same as Redis itself; sentinel uses 26379 by default in production.	Other

Curated from the IANA Service Name and Transport Protocol Port Number Registry. The list focuses on ports developers and sysadmins actually encounter — full registry has 14,000+ entries.

Found this useful?Email

What it does

Quick reference for ~140 well-known TCP/UDP ports — search by number or service name. Web, mail, DNS, DB, SSH, Docker, Kafka, MQTT, more. Developer tools live or die by latency, predictability, and zero learning curve.

Privacy matters: pasting credentials, JWTs, or production data into a third-party server is an audit failure waiting to happen. The gap between “rough estimate” and “defensible number” is exactly where good tooling earns its keep — the math is reproducible, but knowing which inputs matter and what the result means is half the work.

When data flows through external services (analytics, error tracking, ad tags), confirm the tool isolates sensitive inputs. A common pitfall: leaking sensitive data through analytics scripts on the page. Treat the tool’s output as a starting point and validate against authoritative sources for any consequential decision.

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Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.

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How to use it

Enter your query (the value or term you’re looking up).
Pick scope or filter if the lookup supports them.
Read the matching result with relevant context and notes.
Cross-reference against an authoritative primary source for high-stakes use.
Save or copy the result for reuse.

When to use this tool

Sensitive transformations where data shouldn’t hit a third-party server.
Quick one-off transformations that don’t justify a CLI install.
Educational walkthroughs where you want to show the input-output mapping live.
Verifying output of automated pipelines before deploy.

When not to use it

Performance-critical hot paths where browser overhead matters.
Compliance-bound contexts requiring audit trails (SOC 2, HIPAA, PCI).
Bulk transformations across thousands of files (use a CLI batch tool).
Production pipelines where you need versioned, repeatable, scriptable execution.

Common use cases

A DevOps and platform engineers working through port number lookup for a real decision.
A security engineers auditing payloads working through port number lookup for a real decision.
A QA engineers building test fixtures working through port number lookup for a real decision.
A frontend engineers working through port number lookup for a real decision.

Frequently asked questions

Is the output identical to the standard library implementation?: Yes — modern browser implementations of TextEncoder, atob/btoa, crypto.subtle, and so on follow the same standards as Node.js, Python, and others.
What about very large files?: Browser memory limits files at roughly 100MB-2GB depending on browser and OS. For larger files, use a CLI tool or stream processing.
How does this compare to a CLI version?: Functionally equivalent for typical inputs. CLI versions handle larger files, batch processing, and scripting; this is faster for one-off ad-hoc use.
Does my data leave my browser?: No — everything runs in your browser’s JavaScript engine. The page makes no network calls with your input data. View Network tab in DevTools to verify.
Does it work offline?: Yes once the page is loaded. The tool runs entirely client-side; refresh while online to update, but offline use works for cached pages.
Can I use this in production?: For ad-hoc dev-team use: yes. For automated pipelines: use a versioned dependency you control. The browser tool is ideal for the human-in-the-loop step.

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