Port Number Lookup — Common TCP/UDP Service & Protocol Database
Searchable reference for 80+ well-known TCP and UDP ports. Look up any port number or service name to see the official protocol, service description, port range (well-known/registered), and security recommendations for risky ports.
How to Use Port Number Lookup — Common TCP/UDP Service & Protocol Database
How to Use the Port Number Reference:
Search by Port Number: Type a port number in the search box to instantly filter the table. Entering 22 shows SSH; entering 3 shows all ports starting with 3 (3000, 3306, 3389, etc.), letting you explore related ports quickly.
Search by Service Name: Type a service name or keyword to find matching ports. Searching "postgres" returns port 5432, "redis" returns 6379, and "vpn" shows OpenVPN, PPTP, WireGuard, and IPsec entries. Search is case-insensitive and matches service names and descriptions.
Filter by Category: Click any category pill (Web, Database, Remote, Email, Messaging, etc.) to narrow the table to a specific group. Combine a category filter with a text search for precise lookups, such as all Database ports containing "sql".
Read Security Notes: Rows with an amber warning icon (⚠) have associated security recommendations. Click the row to expand and read the note. Security notes explain known risks and recommended mitigations — useful when configuring firewalls or auditing open ports.
Browse the Full Table: Leave the search empty to see all 80+ ports sorted by port number. The table columns show: port number, protocol (TCP/UDP), service name, category, and description. Scroll horizontally on small screens.
Clear Filters: Click the Clear button or remove your search text to reset to the full port list.
Use for Firewall Rules: Use the port, protocol, and service columns to write accurate firewall rules. For example, allowing SSH requires TCP port 22; DNS requires both TCP and UDP on port 53 (TCP for zone transfers, UDP for queries).
Common Use Cases:
- Firewall configuration: Verify which protocol and port a service uses before writing allow/deny rules.
- Security audits: Review which open ports are high-risk and check the security notes for remediation steps.
- DevOps setup: Quickly confirm database, message broker, and monitoring port numbers when configuring services.
- Kubernetes networking: Look up control-plane and node ports (6443, 10250, 2379, 2380) for network policy configuration.
- Incident response: Identify what service is behind an unfamiliar port seen in logs or a port scan.
- Study and certification prep: Reference for CCNA, CompTIA Network+, and Security+ exam preparation.
- Documentation: Confirm correct port numbers when writing runbooks or architecture diagrams.
Tips and Best Practices:
- Port 22 (SSH) is the safest remote access option — prefer it over Telnet (23) or unencrypted RDP.
- Always enable authentication on databases (MongoDB, Redis, Elasticsearch) even on internal networks.
- Use LDAPS (636) instead of LDAP (389) to prevent credential interception.
- Disable Docker's insecure API port (2375) — use the TLS port (2376) with client certificates.
- WireGuard (51820) is the recommended modern VPN — simpler and more secure than OpenVPN or PPTP.
- etcd (2379) holds all Kubernetes secrets — it must never be exposed outside the control plane.
Frequently Asked Questions
Most Viewed Tools
TOTP Code Generator — 2FA Testing Tool
Generate time-based one-time passwords from a TOTP secret key. Enter your base32 secret, choose a period and digit length, and get the current and next codes with a live countdown timer. Useful for testing and debugging 2FA integrations.
Use Tool →JSON to Zod — Schema Generator
Generate Zod validation schema code from a JSON sample object. Infers z.string(), z.number(), z.boolean(), z.array(), z.object(), and z.null() types automatically. Handles nested objects, arrays of objects with optional field detection, and outputs copy-ready TypeScript with import and z.infer type alias.
Use Tool →JSONL Formatter — Line-by-Line Validator
Format, validate, and inspect JSON Lines (JSONL) and NDJSON files. Validates each line individually, reports parse errors by line number, outputs compact JSONL or a pretty-print preview, and lets you download the cleaned file.
Use Tool →TLS Cipher Suite Checker — Strength Analyzer
Check TLS protocol version compatibility and cipher suite strength ratings against current best practices. Supports IANA and OpenSSL cipher names — rates each suite as Strong, Weak, or Deprecated and explains why.
Use Tool →Secret Scanner — API Key & Credential Detector
Scan pasted text, code, or config files for accidentally exposed API keys, tokens, passwords, and private keys. Detects 50+ secret types across AWS, GitHub, Stripe, OpenAI, and more — all client-side, nothing leaves your browser.
Use Tool →Password Entropy Calculator — Crack Time Estimator
Calculate the information-theoretic bit entropy of any password or API key. Detects character set pools automatically, shows the total number of possible combinations, and estimates crack time across five attack scenarios from rate-limited web logins to GPU cracking clusters.
Use Tool →TOML Config Validator — Syntax Error Finder
Validate TOML configuration file syntax and report errors with line numbers. Paste any TOML content — Cargo.toml, pyproject.toml, config.toml — and instantly see a green checkmark with key counts and structure stats, or a precise error message pointing to the exact line. Includes a collapsible JSON structure preview to confirm what was parsed.
Use Tool →Screen Size Converter — Diagonal Dimension Tool
Calculate screen width and height from diagonal size and aspect ratio. Convert between inches and centimeters for displays, TVs, and monitors with instant dimension calculations.
Use Tool →Related DevOps & Infrastructure Tools
IP Subnet Calculator — IPv4 Network Mask & Range Splitter
Enter any IPv4 CIDR to see full subnet details (network address, broadcast, usable hosts, subnet mask, wildcard) and optionally split the network into N equal subnets. Outputs a complete table of subnet ranges for VLAN planning, cloud VPC design, and network segmentation.
Use Tool →User Agent Parser — Browser & Device Decoder
Parse user agent strings to extract browser, operating system, device, and engine information. Essential for web analytics, device detection, and browser compatibility testing.
Use Tool →robots.txt Validator — Crawl Rule Checker
Validate your robots.txt file against the Robots Exclusion Protocol. Checks directive syntax, path formats, Crawl-delay values, and Sitemap URLs. Previews crawl rules per user-agent group. Free and runs entirely in your browser.
Use Tool →MIME Type Finder — File Extension Lookup
Find MIME type for file extensions instantly. Look up media types for images, videos, documents, and more.
Use Tool →Robots.txt Generator — Crawler Control Tool
Generate robots.txt file to control search engine crawlers. Create user-agent rules, allow/disallow paths, set crawl delays, and add sitemap URLs. Perfect for managing bot access to your website.
Use Tool →HTTP Header Analyzer — Security & CORS Audit
Parse and analyze HTTP request or response headers. Identifies categories, explains each header, flags missing security headers, and detects duplicates or suspicious values — entirely in your browser.
Use Tool →Dockerfile Linter — Optimize & Secure Your Container Builds
Lint Dockerfile instructions for best practices, security issues, and layer optimization. Flags unpinned base images, root user, ADD vs COPY, apt-get mistakes, shell-form CMD, and more — with fix guidance for each issue.
Use Tool →Docker Compose Validator — Multi-Container YAML Syntax & Logic Check
Validate docker-compose.yml syntax, service definitions, networks, volumes, and environment variables. Catches YAML errors, broken depends_on references, missing image/build, invalid restart policies, and more — with context-aware hints.
Use Tool →Share Your Feedback
Help us improve this tool by sharing your experience