Public IP vs Private IP Explained
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A public IP is the address that represents your connection on the internet, the one websites, apps and platforms see. A private IP is the address your router gives each device on the local network, such as 192.168.1.5, and it only means something inside that network. NAT links the two: your router swaps the private addresses of your devices for one shared public address on the way out. Knowing the difference tells you which address a proxy actually changes, why every device at home shows the same IP to websites, and why your computer's network settings cannot tell you whether a proxy works.
What a private IP is
Private IPs come from three ranges reserved for local networks: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. Home and office routers hand them out to computers, phones, printers and cameras over DHCP. Millions of networks use 192.168.1.x without conflict because these addresses are never routed on the internet.
They let devices on the same network talk to each other: printing, viewing a camera, opening a shared drive. Websites outside your network never see them.
What a public IP is
A public IP is unique on the internet and assigned by your provider. When you open a page, the server sees that address, looks up its country, provider and ASN, and uses them to decide what content to show, which limits to apply or whether to ask for verification.
A public IP may be dynamic, changing when your modem reconnects, or static. See static vs dynamic IP. To find out which organisation owns a public IP, read what an ASN is.
Public vs private IP at a glance
| Public IP | Private IP | |
|---|---|---|
| Scope | Whole internet | Local network only |
| Assigned by | Internet or hosting provider | Your router or local DHCP server |
| Uniqueness | Unique on the internet at any moment | Unique only within your network |
| Seen by websites | Yes | No |
| Example | 203.0.113.25 | 192.168.1.5, 10.0.0.12 |
| Changes when using a proxy | Websites see the proxy IP instead | No |
NAT and CGNAT: why many devices share one IP
Network Address Translation lets a whole local network reach the internet through one public IP. When your laptop at 192.168.1.5 sends a request, the router replaces the source address with its public IP, remembers the connection and sends the reply back to the laptop. To a website, every device in your home looks like one.
Because IPv4 is scarce, many providers, mobile networks especially, add a second layer called carrier-grade NAT. Your router then receives an address from 100.64.0.0/10 or another private range, and many subscribers share one public IP owned by the provider. The giveaway is a WAN address in your router's admin page that differs from what a what-is-my-IP page shows. You cannot open ports for incoming connections, and your public IP may be shared with strangers.
How to find your public and private IP
- Public IP in a browser: open What is my IP. With a proxy enabled, it shows the proxy's address.
- Public IP from the command line:
curl https://api.ipify.org. Through a proxy:curl -x http://user:pass@ip:port https://api.ipify.org. Full steps are in the cURL proxy setup guide. - Private IP on Windows: run
ipconfigand read the IPv4 Address line. - Private IP on macOS:
ipconfig getifaddr en0for Wi-Fi, or System Settings, Network. - Private IP on Linux:
ip addrorhostname -I. - Phones: open Wi-Fi settings and tap the connected network.
How proxies fit in
A proxy only changes the public IP that websites see. Your device keeps its private address, still reaches the proxy server using your real public IP, and the proxy forwards requests from its own address. After setting up a proxy, check it with an IP checker, not with ipconfig.
- WebRTC can expose addresses: browsers may reveal your real public or local IP through WebRTC. See what a WebRTC leak is.
- Apps that ignore system proxy settings still use your real public IP. Configure the proxy inside the app or route it with a tool such as Proxifier.
- CGNAT is not a problem for proxies: a proxy is an outgoing connection, so you do not need open ports or a public IP of your own.
- Need a fixed public IP of your own: a dedicated IPv4 or static ISP proxy gives you an address nobody else uses, for example a Vietnam proxy.
Frequently asked questions
Is 192.168.1.1 public or private?
Private. It is usually your router's address on a home network and only reachable from inside that network.
Can websites see my private IP?
Normally not; they only see your public IP. Older browsers could expose local addresses through WebRTC, which modern browsers now mostly hide.
Why does my computer show a different IP than an IP checker?
Your computer shows the private address from your router, while the checker shows the public address after NAT, or the proxy IP if one is active. The difference is normal.
How can I tell if my provider uses CGNAT?
Compare the WAN IP in your router with the public IP on a checker. If they differ, or the WAN IP is in 100.64.0.0/10, you are behind CGNAT.
Does a proxy give me my own public IP?
A dedicated proxy from VinaProxy gives you a public IP assigned to one customer and kept for the whole rental period. Websites see it instead of your real IP.
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