Public IP vs Private IP: What's the Difference?
By Administrator
If you've ever peeked at your network settings, you may have noticed your device shows one IP address there, while an online IP checker shows a completely different one. That's not a bug — it's the difference between a private IP and a public IP.
What is a private IP address?
A private IP identifies a device within your local network. Your router assigns one to every connected device so it can route traffic correctly. Private addresses live in reserved ranges and are never routable on the public internet:
10.0.0.0–10.255.255.255172.16.0.0–172.31.255.255192.168.0.0–192.168.255.255
What is a public IP address?
A public IP identifies your entire network to the outside world. Your ISP assigns it to your router, and every device shares it when talking to the internet. It's the address that appears in server logs and geolocation lookups.
How NAT connects the two
So how do many devices share one public IP? Through Network Address Translation (NAT). Your router keeps a table mapping each device's private IP to its connections, swapping the private address for the public one on the way out and reversing it on the way back.
Public vs private IP: side by side
| Aspect | Private IP | Public IP |
|---|---|---|
| Scope | Local network | Entire internet |
| Assigned by | Your router | Your ISP |
| Visible to websites | No | Yes |
| Example | 192.168.1.14 | 203.0.113.42 |
How to find each address
- Public IP: open an IP-checking tool — it shows your public address, location and ISP.
- Private IP: run
ipconfigon Windows, orip addron macOS/Linux.
Only your public IP is exposed online — your private addresses stay inside your home.
Why the difference matters
Knowing which is which helps you set up devices, configure port forwarding, protect your privacy, and troubleshoot connectivity. The reserved private ranges are defined by RFC 1918.
