Last updated: September 14, 2026 · 7 min read

What Is a Public IP Address?

A public IP address is the address your internet service provider assigns to your connection. It is globally routable, which means any server on the internet can send traffic back to it. When you load a website, stream a video, or join a video call, the server on the other end sees your public IP — not the address of your laptop or phone. Think of it as the street address of your whole household: mail from anywhere in the world can reach it, but it says nothing about which room the letter ends up in.

Public IPs are unique across the internet at any given moment. They are handed out in blocks to ISPs and cloud providers by regional registries, which is why a public IP can be traced to a provider and an approximate area. It is also the address that appears in server logs, comment histories, and abuse reports, and the one that gets checked against spam blacklists.

What Is a Private IP Address?

A private IP address is what your router assigns to each device inside your local network — your laptop, phone, TV, printer, and every smart bulb. These addresses come from ranges that were reserved specifically for internal use and are never routed on the public internet:

• 10.0.0.0 – 10.255.255.255 (large corporate networks)
• 172.16.0.0 – 172.31.255.255 (mid-size networks, some ISPs and containers)
• 192.168.0.0 – 192.168.255.255 (almost every home router)

If your device shows an address like 192.168.1.23, that is a private IP. Millions of homes use the exact same internal numbering at the same time without any conflict, because those addresses only need to be unique inside each local network. A private IP is like a room number: meaningful inside the building, meaningless to the outside world.

How the Two Work Together: NAT

Your router bridges the two worlds using Network Address Translation, or NAT. When your laptop (say 192.168.1.23) requests a web page, the router rewrites the request so it appears to come from your single public IP, and remembers which internal device asked. When the reply comes back, it forwards the response to the right room. That is how a dozen devices share one public address.

This is also why the version of IP matters. IPv4 has only about 4.3 billion possible addresses — far fewer than the number of connected devices — so NAT and private ranges became the workaround that keeps IPv4 alive. IPv6 was designed to give every device its own globally unique address and remove the shortage entirely; our guide to IPv4 vs IPv6 covers that shift in detail.

When Your ISP Adds a Second Layer: CGNAT

Some ISPs, especially mobile carriers, run NAT a second time on their own network, so even your router's "public" side gets a shared address. That is called carrier-grade NAT, and it means your public IP is shared with hundreds of other customers. If port forwarding never works for you, or websites keep showing you a city you have never lived in, CGNAT is often the reason.

How to Find Each Address

Finding your public IP is the easy part: it has to be visible to the outside world, so any external service can read it. The GoIPScan home page shows your current public IP instantly, along with the provider and approximate location attached to it.

Your private IP lives on the device itself. On Windows, run ipconfig in a command prompt and look for "IPv4 Address". On macOS and Linux, it is under Wi-Fi details in settings or via ip addr in a terminal. On phones, tap the information icon next to the Wi-Fi network you are connected to. Expect something in the 192.168.x.x range at home — and expect it to be different from what any website reports, which is the whole point.

Which One Do Websites Actually See?

Websites, apps, and game servers only ever see your public IP. Your private address never leaves your local network — NAT strips it out before traffic reaches the internet. So when people worry about being tracked "by IP", it is the public address they mean: it is what advertising networks log, what geolocation databases map, and what shows up if someone checks the address behind a forum post. We break down what that exposure really amounts to in what someone can do with your IP address.

The flip side: hiding your private IP is neither possible nor necessary, and any product that promises to "protect your 192.168 address from hackers" is selling confusion. Privacy tools like VPNs work on the public side, replacing the address websites see with one belonging to the VPN provider.

Security: Private Doesn't Mean Safe

Because private addresses are unreachable from the internet by default, NAT acts as an accidental firewall — nobody outside can connect inward unless you invite them. That protection has limits, though. Port forwarding, UPnP, and misconfigured routers can quietly punch holes that expose internal devices; our guide to open ports explains which ones are risky and how to check yours.

The private network is also only as trustworthy as the devices on it. A compromised smart gadget sits behind the same NAT you do, on the same 192.168 range as your laptop. And if you use a VPN for privacy, remember it only masks the public side — a leaky setup can still reveal your real address, which is worth verifying with a VPN leak test.

Frequently Asked Questions

Is 192.168.1.1 my public IP?

No. Anything starting with 192.168 is a private address; 192.168.1.1 is usually your router's internal address, which doubles as the login page for its admin panel. Your public IP is assigned by your ISP and looks nothing like it — check the GoIPScan home page to see it.

Can two devices have the same IP address?

Two devices on different home networks can happily share the same private IP — millions of laptops are 192.168.1.23 right now. Inside one network, though, a duplicate private IP causes an address conflict and both devices misbehave. Public IPs must be unique across the whole internet at any given time, although with CGNAT many customers can share one from the website's point of view.

Does my public IP ever change?

For most home connections, yes — ISPs typically assign public IPs dynamically, so yours can change after a router reboot or after a lease expires. Some connections keep the same address for months. Your private IPs are managed by your router and can also change, unless you reserve fixed addresses for specific devices in the router settings.

Can someone hack me if they know my private IP?

Knowing a private IP is useless from outside your network — the address simply does not route across the internet. It only becomes relevant if an attacker is already inside your network, for example on the same public Wi-Fi. Your public IP is the externally visible surface, and even that mostly exposes you to scanning of any ports you have left open.

Does a VPN change my private IP address?

No. A VPN replaces the public IP that websites see, and typically adds a new internal address for the tunnel itself, but your device keeps its private address on your local network. That is expected — the private address was never visible to websites in the first place.