Free Network & IP Utility Tools
A growing collection of browser-based networking tools for IT professionals, system administrators, and developers. No installs, no signups — just open and use.
Tools
LiveWhat Is My IP Address?
Instantly find your public IPv4 address with geolocation details including city, region, country, and ISP.
→MAC Address Vendor Lookup
Enter any MAC address to identify the hardware manufacturer using the IEEE OUI database.
→DNS Record Checker
Query A, AAAA, MX, TXT, CNAME, and NS records for any domain using Google DNS-over-HTTPS.
→Reverse DNS Lookup
Find the hostname (PTR record) associated with any IPv4 address via in-addr.arpa resolution.
→IPv4 Subnet Calculator
Calculate network address, broadcast address, usable host range, and subnet mask from any IP and CIDR prefix.
→IP Address ↔ Binary Converter
Convert between dotted-decimal, binary, hexadecimal, and integer IP formats with class and scope detection.
→Common Port Number Reference
Searchable database of 75+ well-known TCP and UDP port numbers with service names and descriptions.
Guides
LiveHow to Find Your Public IP Address
What your public IP reveals, why it matters, and the fastest ways to find it on any device.
→What Is a MAC Address?
How MAC addresses work, where to find yours, and why vendor lookups are useful for network management.
→DNS Records Explained: A, AAAA, MX, CNAME, TXT, NS
A plain-English breakdown of every common DNS record type and when each one comes into play.
→What Is Reverse DNS and When Do You Need It?
How PTR records work, why email deliverability depends on them, and how to check yours.
→Subnetting Made Simple: A Beginner’s Guide to CIDR
Learn CIDR notation, subnet masks, and how to divide networks — with worked examples.
→IP Address Formats: Decimal, Binary, Hex, and How to Convert
Why IP addresses have multiple representations and how to move between them.
→Common Network Ports: What They Are and What They Do
A practical overview of well-known ports, what services use them, and why they matter for security.
Deep Dives
LivePublic vs. Private IP Addresses
What separates public and private address space, NAT, and how traffic gets routed between them.
→How DNS Works: A Plain-English Walkthrough
The full DNS resolution chain from browser to authoritative nameserver, step by step.
→IPv4 vs. IPv6: What’s Changing and Why
Address exhaustion, dual-stack networking, and what the transition means for everyday infrastructure.
→How to Troubleshoot Network Connectivity
A step-by-step diagnostic workflow using ping, traceroute, DNS checks, and the tools on this site.
→What Is a Firewall? Ports, Rules, and Traffic Filtering
How firewalls use port numbers and rules to control traffic, and how to read a rule set.
→VLSM and Supernetting: Beyond Basic Subnetting
Variable-length subnet masks, route aggregation, and when to use them in real network designs.
→Network Basics: The OSI Model in Plain Language
All seven layers explained without the jargon, with real-world examples at each level.