IP essentials
What is an IP address? Public vs private explained.
An IP address is a network address used to deliver traffic to the right destination. Your device can have several addresses at once. The address shown by a website is not necessarily the one listed in your computer's network settings.
Three places to look, three different answers
| Address | Where to find it | What it helps with |
|---|---|---|
| Device's local address | Wi-Fi or Ethernet settings, such as 192.168.1.25. | Reaching a printer, NAS or another device on the same network. |
| Router's WAN address | Your router's Internet or WAN status page. | Understanding the connection between your router and the upstream network. |
| Public address seen by a website | Check my IP. | Giving support the address observed for this browser request. |
Public vs private IPv4 addresses
Private addresses can be reused in separate networks. The three private IPv4 ranges are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. The middle range covers 172.16.0.0 through 172.31.255.255; not every address beginning with 172 is private. These ranges are defined in RFC 1918.
On a typical home IPv4 network, your router uses network address translation (NAT) so several devices can share one public address. Two laptops can therefore show different local addresses but the same public address. A public address is not, by itself, proof that a device accepts incoming connections: routing, firewalls and service configuration still matter.
Other special ranges exist too. For example, 127.0.0.1 refers to the device itself, and 100.64.0.0/10 is shared address space used by some providers. The IP range checker explains these distinctions without sending the entered address to our server.
Why the WAN address may also be private
Your router may sit behind another router or your provider's NAT. In that case its WAN address can differ from the public IPv4 address we see. A mismatch needs context; it does not automatically prove carrier-grade NAT. Follow the CGNAT checking guide before changing port-forwarding settings.
What about IPv6, VPNs and changing addresses?
IPv6 has different address categories, and a device may hold several IPv6 addresses alongside IPv4. Read the IPv4 vs IPv6 guide. When this request travels through a VPN or proxy, the site normally sees its exit address. That observation does not test other applications or certify privacy.
If an address changes between visits, first compare the same address family and network. The IP address changes guide includes a simple observation checklist. To find your local address on a Mac, use the Mac instructions.