IP in CIDR Checker
Check whether one address is inside a CIDR block. IPv4 and IPv6 are handled separately, and a mixed pair is rejected. The network is normalized first, so 192.168.1.50/24 is the same block as 192.168.1.0/24.
How the test works
Mask both the address and the network with the prefix, then compare. If the masked values match, the address is inside. 192.168.1.10 is inside 192.168.1.0/24. 192.168.2.10 is not, because the third octet differs inside the network portion.
Questions
Yes. Membership is about the prefix, not about whether the address is a usable host. 192.168.1.0 is inside 192.168.1.0/24.
No. The families are not comparable. Enter an IPv6 network such as 2001:db8::/32 for an IPv6 address.
Sources
Reviewed 8 October 2026. The methodology page records what these labels do not cover.
Related tools
- Subnet CalculatorNetwork, broadcast, mask, and usable hosts for an IPv4 address and prefix.
- CIDR CalculatorStart from CIDR notation and see the exact block it names.
- IP Range CalculatorInclusive block bounds, then the usable host range.
- IPv6 Subnet CalculatorPrefix, compressed form, and the exact IPv6 range.
