Public vs Private IP Address
Public and private IP addresses solve different problems. Public addresses are routable on the internet; private addresses are used inside local networks.
Updated 2026-08-08Private addresses stay local
Common private IPv4 ranges include 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. These addresses appear in homes, offices and cloud private networks.
Because private ranges are reused everywhere, they do not identify a public internet endpoint by themselves.
Public addresses face the internet
A public address is assigned by an ISP, hosting provider or cloud network and can be routed globally unless firewall rules block traffic.
NAT often lets many private devices share one public IPv4 address.
When it matters
Use public IP checks for allowlists and remote access. Use private IP and subnet tools when planning internal networks or diagnosing LAN routing.
Quick answers
Can a private IP be looked up on the public internet?
No. A private address is only meaningful inside the network where it is used.