CIDR / Subnet Calculator
Enter a CIDR block and get network address, broadcast, usable host range, wildcard mask, and subnet size — all computed locally.
You don't control software you don't possess
The Network Knife is the answer
Terms change. Features disappear. Accounts get suspended. Servers go down. When you depend on someone else's infrastructure, you depend on their decisions. Sovereign tools. Single HTML files you own. No accounts, no terms, no kill switch.
The Network Knife is a single-file knife with 6 tools that runs entirely in your browser. The Network Knife packages six essential network engineering utilities into a single HTML file. Calculate subnets, plan VLSM allocations, inspect MAC addresses, convert IP addresses to binary, look up HTTP status codes, and reference well-known ports — all without an internet connection. Because the best network tools shouldn't require one.
WHAT'S INSIDE
6 tools in a single HTML file
IP Binary Viewer
Convert IPv4 addresses to binary with colour-coded octets. See exactly which bits belong to the network and which to the host.
MAC Address Inspector
Paste a MAC address and identify the vendor (OUI lookup), format it in common notations, and check if it's unicast, multicast, or locally administered.
VLSM Architect
Plan Variable Length Subnet Mask allocations from a base network. Enter subnet requirements and get an optimised, non-overlapping allocation plan with waste analysis.
HOW IT WORKS
Three steps. No setup.
1
Download the file
Purchase The Network Knife and download a single HTML file. No installer, no account, no setup.
2
Open in any browser
Double-click to open in Chrome, Firefox, Safari, or Edge. Works on any operating system.
3
Start working
Your data stays in your browser's local storage. Nothing is uploaded. Ever.
COMPLIANCE & GEOGRAPHY
Global
Works in any country. No server dependency, no regional restrictions.
FAQ
Frequently Asked Questions
How does The Network Knife solve the digital sovereignty problem?
The Network Knife runs entirely in your browser. Terms change. Features disappear. Accounts get suspended. Servers go down. When you depend on someone else's infrastructure, you depend on their decisions. Sovereign tools. Single HTML files you own. No accounts, no terms, no kill switch. CIDR calculator, IP binary viewer, MAC inspector, VLSM architect, HTTP status codes, and port reference. The irony: network tools that don't need a network.
Is my data safe with The Network Knife?
Yes. The Network Knife is a single HTML file. It never connects to any server. Your data stays in your browser's local storage on your device.
What makes The Network Knife different from cloud tools?
Cloud tools require internet, charge subscriptions, and store your data externally. The Network Knife is a one-time purchase ($39), works offline, and never transmits data.
Is The Network Knife really just one file?
Yes. The Network Knife is a single HTML file containing 6 tools. Download it, open it in any browser, and start working. No installation, no dependencies, no accounts.
No cloud One fileOne-time purchase
Get The Network Knife — $39Sovereignty as a Service