Every IP calculation,
in one fast toolkit
Subnet, summarize, convert and design networks with precision-grade tools. No sign-up, no ads, and every byte stays in your browser.
100% client-side · works offline · no IP data ever leaves your device
The toolkit
Pick a calculator
Each tool is purpose-built, instant, and copy-ready. Click any card to get started.
IPv4 Subnet Calculator
Network, broadcast, host range, mask, wildcard, class & usable hosts — all synced.
Open tool →CIDR Calculator
Turn any CIDR block into its address range, total & usable host count instantly.
Open tool →IP Base Converter
Convert an IPv4 address between dotted-decimal, integer, hexadecimal & binary.
Open tool →Wildcard Mask Calculator
Translate subnet masks to wildcard (inverse) masks for ACLs & OSPF.
Open tool →VLSM Calculator
Carve a parent network into right-sized subnets from a list of host requirements.
Open tool →Supernet / Summarization
Aggregate multiple networks into the smallest covering supernet (route summary).
Open tool →IPv4 to IPv6 Converter
Map an IPv4 address into IPv4-mapped IPv6 notation, compressed & expanded.
Open tool →IPv6 Compress / Expand
Compress, fully expand and inspect any IPv6 address with prefix details.
Open tool →IPv6 to IPv4 Converter
Extract the embedded IPv4 from IPv4-mapped, 6to4, NAT64 and IPv4-compatible IPv6 addresses.
Open tool →IPv6 Subnet Calculator
Get the network, range, total addresses and divide an IPv6 prefix into subnets.
Open tool →MAC Address Tool
Normalise MAC formats, detect unicast/multicast & local bits, derive EUI-64.
Open tool →IP Extractor
Pull every IPv4 and IPv6 address out of any block of text or log paste.
Open tool →Subnet Cheat Sheet
The full /0–/32 reference: prefix, mask, wildcard, hosts and subnet counts.
Open tool →DNS Lookup
Resolve A, AAAA, MX, NS, TXT, CNAME and SOA records for any domain.
Open tool →Reverse DNS (PTR)
Find the hostname (PTR record) behind an IPv4 or IPv6 address.
Open tool →What Is My IP
See the public IP address and request headers your browser is sending.
Open tool →IP WHOIS Lookup
RDAP/WHOIS ownership, network name, country and registry for any IP.
Open tool →ASN Lookup
Look up the Autonomous System (ASN, operator, ISP) for an IP or AS number.
Open tool →IP Geolocation
Locate any IP — country, region, city, coordinates, timezone and ISP.
Open tool →IP Range ↔ CIDR
Convert a start–end IP range into the smallest CIDR blocks, and back again.
Open tool →Blacklist (DNSBL) Check
Check whether an IP is listed on common email spam blacklists (DNSBLs).
Open tool →Port Checker
Test whether a single TCP port is open and reachable on a public host.
Open tool →Random IP Generator
Generate random IPv4 or IPv6 addresses, optionally within a CIDR range.
Open tool →Bandwidth Calculator
Work out data-transfer time, throughput and download size across units.
Open tool →Dig (DNS Query)
Run a real dig query and see the full DNS answer — header, sections, TTLs and query time.
Open tool →No tools match “”
Try a different keyword — like “subnet”, “ipv6”, “dns” or “mac”.
From the blog
Learn the concepts
IPv6 for People Who Know IPv4
No more running out of addresses. A quick tour of IPv6 notation, prefixes and the :: shortcut.
Read article →CIDR vs VLSM: When to Use Which
CIDR aggregates, VLSM subdivides. Here is how the two fit together in real network design.
Read article →
Subnetting Explained: From /24 to /30 in Plain English
What a subnet mask really does, how to read CIDR notation, and how to split a network without the headache.
Read article →Why this toolkit
Built for engineers who live in the CLI
No trackers, no logins, no “upgrade to unlock”. Just clean, accurate networking math you can trust during a maintenance window at 3 a.m.
Instant results
Calculators run as you type — no page reloads.
Private by default
Subnet math is computed locally; lookups only hit DNS/registries when you ask.
Copy-ready output
One click to copy any field to your clipboard.
Quick example
192.168.1.10 /26 resolves to: