Public IP: your address on the internet
Your internet provider gives your router one public IP. It is unique on the whole internet at that moment, and every website you visit sees it. All devices in your home share it: your phone, laptop and TV all reach the internet through the same public IP.
Private IP: your address at home
Your router gives each device its own private IP, like 192.168.1.23. These addresses only work inside your network. Millions of homes use the very same private numbers, which is fine, because they never leave the house.
The router keeps a list of which device asked for what, and swaps private and public addresses as traffic goes in and out. This is called NAT (network address translation).
Private IP ranges
These address blocks are reserved for private networks, so you'll never see them as a public IP:
| Range | Short form | Typical use |
|---|---|---|
| 10.0.0.0 – 10.255.255.255 | 10.0.0.0/8 | Offices, some routers |
| 172.16.0.0 – 172.31.255.255 | 172.16.0.0/12 | Offices, Docker |
| 192.168.0.0 – 192.168.255.255 | 192.168.0.0/16 | Most home routers |
| 100.64.0.0 – 100.127.255.255 | 100.64.0.0/10 | Shared by providers (CGNAT) |
| fc00:: – fdff:… | fc00::/7 | Private IPv6 (unique local) |
| fe80:: – febf:… | fe80::/10 | IPv6 link-local, one cable or Wi-Fi only |
How to find your private IP
- Windows: open Command Prompt, type
ipconfig, and look for "IPv4 Address". - Mac: open Terminal and type
ipconfig getifaddr en0(Wi-Fi), or open System Settings → Wi-Fi → Details. - Linux: type
hostname -Iorip -4 addr. - iPhone: Settings → Wi-Fi → tap the (i) next to your network → IP Address.
- Android: Settings → Network & internet → Internet → tap your Wi-Fi network. The exact menu names differ between phone makers.
Tip: if the "WAN" or "Internet" IP in your router's settings is different from the public IP above, your provider probably uses CGNAT (see the questions below).