Network Tools
Free utilities for network administrators and IT professionals, built with privacy in mind. Tools only use third‑party services where absolutely necessary.
Subnet Calculator
Calculate all valid subnets and ranges from any IPv4 or IPv6 address. View CIDR blocks, subnet masks, and IP quantities.
Crontab Helper
Parse, validate, and understand cron expressions. See next execution times and build schedules interactively.
Chmod Helper
Calculate Linux/Unix file permissions. Convert between octal, symbolic, and rwx strings (incl. setuid/setgid/sticky).
Regex Helper
Build, test, and understand regular expressions. Real-time pattern matching with explanations and syntax reference.
Password Generator
Generate strong, memorable XKCD-style passphrases with optional numbers and symbols.
MAC Vendor Lookup
Identify device manufacturers from MAC addresses using the official IEEE OUI database. Supports batch lookup, vendor search, and format conversion.
IP Address Lookup
Look up IP geolocation, ASN, and registration details using RDAP and MaxMind (via a lightweight API backend).
Privacy shields
- Green shield — runs entirely in your browser (inputs not sent to a server)
- Blue shield — relies on external services (see each tool’s Privacy section for details)