Subnet API
A fast, fully-local IP and subnet calculator: validate IPv4 and IPv6 addresses with type classification (private, public, loopback, link-local, multicast, CGNAT or reserved), compute CIDR subnet details (network, netmask, wildcard, broadcast, first and last host, total addresses and usable hosts, with IPv6 network and range size), check whether an address falls inside a CIDR block, and convert addresses (IPv4 to integer, hex and binary; IPv6 expand and compress). Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for devops, network automation, IPAM, firewall and ACL tooling and cloud infrastructure.
api.oanor.com/subnet-api