FREE · NETWORK & IT INFRASTRUCTURE
IP in Subnet Checker.
Check whether a list of IP addresses belongs to one or more networks, with the most specific matching block for each address.
- Outside every network
- 3
- Invalid lines
- 0
- Networks
- 4
Results
| Address | Inside? | Most specific network | Address type |
|---|---|---|---|
| 10.20.30.40 | Yes | 10.0.0.0/8 | Private (RFC 1918) |
| 192.168.10.255 | Yes | 192.168.10.0/24 | Private (RFC 1918) |
| 192.168.11.1 | No | — | Private (RFC 1918) |
| 172.31.255.254 | Yes | 172.16.0.0/12 | Private (RFC 1918) |
| 8.8.8.8 | No | — | Public (globally routable) |
| 2001:db8:1:abcd::5 | Yes | 2001:db8:1::/48 | Documentation (RFC 3849) |
| 2001:db8:2::1 | No | — | Documentation (RFC 3849) |
- An IPv4 address never matches an IPv6 network, including IPv4-mapped ::ffff: forms.
How to use IP in Subnet Checker
List networks on the left and addresses on the right, one per line. The table marks each address and can be exported as CSV.
How it works
Each address is compared with every network by masking it with the network prefix; when several match, the longest prefix is shown, as a router would choose.
Example
With 10.0.0.0/8 and 192.168.10.0/24, 10.20.30.40 matches /8, 192.168.10.255 matches /24 and 8.8.8.8 matches nothing.
Questions about IP in Subnet Checker
Is IP in Subnet Checker free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Up to 10,000 addresses. IPv4 addresses never match IPv6 networks. Everything is calculated in your browser; nothing is sent or probed on the network. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.