Network Tools
Network utilities that run entirely in your browser: IPv4 subnet calculators and address converters, MAC address lookups, and IPv6 ULA generators. No servers, no logs.
IPv4 Subnet Calculator Online (CIDR) Parse any IPv4 address or CIDR block and get the netmask, network address, host range, broadcast address, and size — free, in your browser. IPv4 Address Converter (Decimal, Hex, Binary) Convert an IPv4 address to decimal, hexadecimal, binary, and IPv6-mapped notation in one place — free, instant, and in your browser. IPv4 Range to CIDR Expander Online Turn an IPv4 start–end range into the smallest enclosing CIDR block, with the expanded address count shown — free and in your browser. MAC Address Lookup (Vendor Finder) Find the manufacturer behind any MAC address using the IEEE OUI registry — free, offline once loaded, and resolved in your browser. Random MAC Address Generator Online Generate random MAC addresses with an optional vendor prefix, your choice of separator and letter case — free, instant, in your browser. IPv6 ULA Generator (RFC 4193) Generate a unique-local IPv6 address block (/48) for your private network using the RFC 4193 method — free, computed in your browser.