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Private vs Public IP Addresses Explained

Updated 4 min readby IP Checker editorial team

The difference between private IPs used inside your home or office network and the public IP your ISP assigns you.

A private IP address is used inside a local network. Common ranges include 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. These addresses are not routable on the public internet.

How your router bridges the two

Your router performs Network Address Translation (NAT). It assigns private IPs to your devices and, on outbound requests, swaps the source address to its single public IP. Replies come back to the router, which forwards them to the right device.

Why this matters

Many devices in a home share a single public IP. If a website blocks an address, it can affect multiple users on the same network. This is also why your phone and laptop usually appear with the same public IP when on the same Wi-Fi.

FAQ

Can two networks use the same private IP?

Yes — private ranges are intentionally reusable across networks because they never appear on the public internet.

Related

Sources: ip-api documentation, regional internet registries (ARIN, RIPE, APNIC, LACNIC, AFRINIC), and BGP routing data.