Tools built for network engineers
Fast, accurate, ad-light utilities for networking and IT work — subnetting, security, and more. Everything runs in your browser; nothing is ever logged or stored.
IP Subnet Calculator
Calculate network address, subnet mask, broadcast, CIDR range, and usable hosts for IPv4 and IPv6.
Open tool SecurityPassword Generator
Generate strong, cryptographically random passwords and passphrases — nothing ever leaves your browser.
Open tool NetworkingDNS Lookup
Check A, AAAA, CNAME, MX, TXT, NS records for any domain — compared across Cloudflare and Google DNS.
Open toolPort Checker
Check whether a specific port is open on a given host — useful for debugging connectivity issues.
MAC Address Lookup
Identify the hardware vendor behind any MAC address using the OUI prefix.
Why NetCalcTools?
NetCalcTools is a growing collection of free, focused utilities for network engineers, system administrators, students, and anyone working with IP addressing, DNS, or basic security hygiene. Every tool is designed to be fast, accurate, and free of clutter — no sign-up walls, no intrusive ads, and no unnecessary data collection.
All calculations and generation happen entirely in your browser. Nothing you enter is ever transmitted to a server or stored — see our Privacy Policy for details.