Networking / IP Tools — CIDR, Subnets, Ranges
Five browser-local utilities: subnet calculator, IP address converter, range→CIDR, CIDR summarize, and IP-in-subnet checks. IPv4 and IPv6 from day one. Also useful: number-base-converter for numeric bases (not CIDR math).
Subnet Calculator
IPv4/IPv6 network, mask, hosts, and address class — browser-local.
IP Address Converter
IPv4/IPv6 decimal, hex, binary, compress/expand — local forms.
IP Range to CIDR
Minimal exact CIDR cover for an inclusive start–end range.
CIDR Summarize
Merge or dedupe CIDR lists with fail-fast validation.
IP in Subnet
Check IP ∈ CIDR or whether two CIDRs overlap.