What is a public IP address?
Understand public and private IP addresses, why your IP changes, and what an IP lookup actually shows.
The address websites can see
When your device connects to a website, the request carries a source IP address. The website uses that address as part of sending a response back through the network. IPNIXA shows the public address observed for your request.
This is not necessarily an address assigned directly to your laptop. A home router, mobile carrier, workplace gateway or VPN server may share its public address with many devices. Two people can therefore see the same public IP without using the same computer.
A concrete example: at home, your laptop might be 192.168.1.10, your phone 192.168.1.11 and your TV 192.168.1.12. A website visited from any of them sees one and the same address, for example 203.0.113.42, because all three leave the house through the same router. The examples on this site use address ranges reserved for documentation, so they never belong to a real person.
Public and private addresses have different jobs
A private address identifies a device inside a local network. Common examples begin with 192.168 or 10. Your router can translate traffic between private device addresses and a public IPv4 address, a process called network address translation.
A website normally cannot show your private Wi-Fi address just by inspecting the request it receives. To find that address, open the network details in your device settings. IPv6 networks can assign globally routable addresses directly to devices, with firewall rules controlling incoming traffic.
| Public IP address | Private IP address | |
|---|---|---|
| Assigned by | Your internet provider, mobile carrier or VPN service | Your router (usually through DHCP) |
| Works | Across the internet | Only inside your local network |
| Unique? | Unique on the internet at a given moment, but may be shared by many devices | Reused in millions of separate networks |
| IPv4 examples | 203.0.113.42, 198.51.100.7 | 192.168.1.10, 10.0.0.5, 172.16.4.20 |
| How to see it | Open IPNIXA in a browser | Your device’s Wi-Fi or network settings |
How your connection gets its public address
On a home broadband line, your router asks the provider for an address when it connects, using DHCP or PPPoE depending on the provider. The provider hands out an address from its pool and records which customer is using it.
On mobile data, the address you see usually belongs to the carrier’s gateway rather than to your phone. Many carriers place thousands of customers behind a shared IPv4 address with carrier-grade NAT, while also giving each phone its own IPv6 address.
With IPv6, providers typically delegate a whole block of addresses (a prefix) to your router, and each device builds its own public IPv6 address from that block. That is why a dual-stack connection can show one shared IPv4 address but a different IPv6 address on every device.
- Home broadband: the router holds the public IPv4 address; devices behind it share it.
- Mobile data: the carrier gateway holds the public IPv4 address; IPv6 is often per device.
- Office or school network: a central firewall holds the address for everyone in the building.
- VPN, proxy or privacy relay: the service’s exit server holds the address websites see.
Why your address may change
Internet providers can assign addresses dynamically. Reconnecting, changing network, switching between mobile data and Wi-Fi, or changing a VPN server may change the result. A static address is arranged with a provider and is not something an IP lookup can reliably infer from one visit.
To compare connections, note the result, switch networks and reload the page. Make sure you are comparing the same address family: an IPv4 result and an IPv6 result can both belong to the same connection.
- Your router restarts, or its address lease expires and the provider assigns a new one.
- You move from Wi-Fi to mobile data, or between mobile cells while traveling.
- You turn on a VPN, proxy, iCloud Private Relay or a browser’s built-in privacy proxy.
- Your provider reorganizes its network and renumbers customer addresses.
- Your device rotates its temporary IPv6 address, which most operating systems do regularly for privacy.
How to check and compare your public IP
A quick comparison tells you whether a change of network, a VPN or a router restart actually changed what websites see.
- Open IPNIXA in your browser. The IPv4 address is shown first; if your connection also has IPv6, select “Show IPv6 address”.
- Select Copy IP and paste the address somewhere, with the time and the network you are on.
- Change one thing only: switch from Wi-Fi to mobile data, connect a VPN, or restart the router.
- Select Refresh and compare. A different address means your traffic now leaves through a different exit point.
- Compare the network organization as well. If it changes from your provider to a hosting company, the new exit is a VPN or proxy server.
What this result does not prove
A visible public IP is a normal part of internet communication. Its visibility alone does not mean your device has been compromised. The result does not test your firewall, confirm that a VPN is secure, or identify a person.
For troubleshooting, share only the information needed with someone you trust. Your public IP may reveal your network provider and approximate network location. IPNIXA does not keep lookup results in an application database.
Frequently asked questions
Is my public IP address the same as my device’s IP address?
Usually not. Your device has a private address inside your network, such as 192.168.1.10, and the router or carrier gateway presents a shared public address to the internet. On IPv6 the two are closer, because devices often receive their own public IPv6 address.
Can two people have the same public IP address?
Yes. Everyone in a household, office, café Wi-Fi or mobile carrier gateway can share one public IPv4 address at the same time, and so can everyone connected to the same VPN server.
Should I hide my public IP address?
Most people do not need to. Every website you visit receives it as part of normal communication. A VPN or privacy relay can hide it from websites when you prefer that, for example on untrusted Wi-Fi; keeping your router and devices updated matters more for security.
Why does IPNIXA show one address first?
The main readout shows the address used by this request, with matching network metadata. A separate check looks for the other family. Its result appears without changing the main address or implying that both addresses have the same location.