CIDRift Source on Codeberg

CIDR relationships, made explicit

Find overlapping network blocks before deployment.

Paste a list of strict IPv4 or IPv6 CIDRs and see duplicates, containment, canonical ranges, and address counts. Everything runs in this page—no uploads, cookies, or tracking.

01 / CHECK

Enter one CIDR per line

Accepted: strict IPv4 or IPv6 CIDR such as 192.0.2.0/24, 2001:db8::/32, or valid IPv6 with a dotted IPv4 tail. Full-line # comments are allowed; host bits, inline comments, labels, and unsupported range formats are refused. Input is limited to 1 MiB, 10,000 lines, and 20 reported parse errors.

03 / BOUNDARY

Math is not reachability.

CIDRift compares the supplied address ranges locally. It does not scan a network, resolve DNS, inspect interfaces, test reachability, audit firewall rules, validate routes, query cloud providers, or approve a deployment.

Strict parsing rejects host bits, malformed addresses, inline comments, labels, and unsupported notation instead of guessing what the input meant. Verify any proposed network plan against the systems and policies that will use it.