// TOOLS

Security Tools

🌍 CIDR & Subnet Calculator

Network, broadcast, mask, wildcard, range and hosts — IPv4 and IPv6. Split a network into subnets and check whether an IP falls inside a range. BigInt-backed, no precision loss.

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Frequently asked questions

Does it support IPv6?
Yes, IPv4 and IPv6, using BigInt so no precision is lost (a /48 is 1.2×10²⁴ addresses).
What does it compute?
Network, broadcast, mask, wildcard, usable range, host count and scope (private RFC1918, ULA, CGNAT…). It also splits a network into subnets and checks whether an IP falls inside a range.
Why are there 2 fewer hosts than addresses?
In IPv4, the network and broadcast addresses are not assigned to hosts, so a /24 has 256 addresses but 254 usable hosts.