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) — Free 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) — Free 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 — Free 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) — Free 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 — Free 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) — Free Generate a unique-local IPv6 address block (/48) for your private network using the RFC 4193 method — free, computed in your browser.