IP in CIDR checker — bulk allow/deny list test (local)
Paste IPs and CIDR blocks to see which addresses fall inside your firewall rules, VPN routes, or ACL ranges. Supports IPv4 and IPv6 with tab-separated export.
Frequently asked questions
No. IP and CIDR membership checks run entirely in this tab—lists are not uploaded. Nothing is sent to LocalTools servers for processing.
Yes. When an address falls inside overlapping ranges, every matching CIDR is listed in the results table and TSV export.
No—the checker expects network addresses on the CIDR side (same rule as the CIDR aggregator). Use the Subnet Calculator to normalize a host IP to its network.