What is an IP address?
An IP address, short for Internet Protocol address, is a numeric identifier assigned to a device or network interface so that data can be sent to the correct destination. When you open a website, your browser and the destination server use IP routing to exchange information. Without IP addressing, devices would not know where to send or receive traffic.
In practice, most visitors are asking about their public IP address. That is the address visible to websites, APIs, and external servers. It is usually assigned by your internet service provider or by the exit node of a VPN, proxy, or mobile carrier network.
Public vs private IP address
A public IP address is reachable from the wider internet. A private IP address is used only inside a local network, such as your home Wi‑Fi or office router. For example, your laptop may have a private IP inside your router network, while the router itself exposes one public IP to websites. That is why several devices in one house can appear online under the same public IP.
- Public IP: visible to websites and external services.
- Private IP: used inside your local network.
- Router/NAT: often translates multiple private devices behind one public IP.
IPv4 vs IPv6
IPv4 is the older and shorter address format, typically shown as four numbers separated by dots, such as 203.0.113.42. IPv6 is newer, longer, and designed to support a vastly larger address space, such as 2a00:1450:4001:81b::200e. Many mobile networks and modern ISPs already prefer IPv6 where available.
If your phone shows a long address with colons while your computer shows a shorter dotted address, that usually means one device is using IPv6 and the other is using IPv4. This is normal and does not mean your site is broken.
Why does my IP location change?
IP geolocation is based on ISP, carrier, and network allocation databases, not on GPS. Because of that, IP location is approximate. Your detected city or region may reflect your ISP gateway, carrier exit point, or VPN server rather than your exact physical location. This is especially common on mobile networks, business connections, and privacy tools.
- Your location can change when you switch between Wi‑Fi and mobile data.
- Your location can change if your ISP rotates addresses.
- Your location can appear wrong if you use a VPN or proxy.
Can a VPN change my IP address?
Yes. A VPN usually replaces your visible public IP with the address of the VPN exit server. That means websites may detect a different city, state, country, ISP, or ASN than your real internet connection. Proxy services and corporate secure gateways can create the same effect. For a deeper explanation of the fields shown in an IP checker, see our IP lookup guide.
How to check your IP address
The fastest way is to use a live IP lookup page that reads your public IP from the browser and enriches it with geolocation data. On our homepage, you can view your IPv4 or IPv6 address, VPN or proxy status when available, city, state, country, postal code, time zone, ISP, and ASN.
If you want to compare results, test once on Wi‑Fi and once on mobile data. If the addresses differ, that is expected because the traffic may be routed through different networks.