Network Utilities

IP Lookup, CIDR Calculator, MAC Address Lookup, and Port Number Lookup

Examples:

Subnet Calculator

Here's the subnet information about the given CIDR.

Get JSON results via command line with either curl or wget.

Try it:
curl "https://steamr.com/?q=3.87.118.5/24"

{
    "start": "3.87.118.0",
    "end": "3.87.118.255",
    "bits": 24,
    "netmask": "255.255.255.0",
    "size": 256
}