What an IP address looks like
There are two versions in use. IPv4 is four numbers from 0 to 255 separated by dots (192.168.1.10), about 4.3 billion possible addresses. IPv6 is eight groups of hexadecimal digits separated by colons, with runs of zeros shortened to :: (2001:db8::1). It has enough addresses for practically unlimited devices. IPv4 vs IPv6 covers the differences.
Public and private addresses
Your ISP gives your router a public IP, the address the rest of the internet sees. Inside your home, the router gives each device a private IP from reserved ranges like 192.168.x.x or 10.x.x.x, which can't be reached from the internet. When a device goes online, the router swaps its private address for the public one (NAT). Public vs private IP explains this, and CGNAT, in detail.
| Type | Example | Where to see it |
|---|---|---|
| Public IP | 203.0.113.25 | What is my IP |
| Private IP (your device) | 192.168.1.23 | Device Wi-Fi or network settings |
| Router (default gateway) | 192.168.1.1 | Router IP finder |
How devices get an IP address
When a phone joins your Wi-Fi, it asks the router for an address using DHCP and gets a private IP for a set time (a lease). The router in turn gets its public IP from the ISP the same way, or through a PPPoE login on many DSL and fibre connections. That's why addresses change over time unless you set a reservation or pay for a static IP.
What your IP reveals, and what it doesn't
A public IP reveals which ISP or network you're on and an approximate location, usually a city or region, derived from databases that are sometimes wrong. It doesn't reveal your name, street address or browsing history. Websites use it for rough location, fraud checks and rate limits. You can see what yours shows with What is my IP or look up any address with IP lookup.
A VPN replaces your visible public IP with the VPN provider's; it doesn't change your private IP.
Special addresses worth recognising
127.0.0.1and::1: “this device” (loopback).169.254.x.x: the device couldn't get an address from the router. Usually a Wi-Fi or DHCP problem; reconnect or restart the router.100.64.x.x – 100.127.x.x: carrier-grade NAT, meaning your ISP shares public addresses between customers.0.0.0.0and addresses ending in.255: not normal device addresses.
Common questions
Can someone find my home address from my IP?
Not from the IP alone. A public IP reveals your ISP and an approximate area, often just the city or region, and sometimes it's wrong. Only your ISP can link an IP to a customer, and they share that only through legal processes.
Why does my IP address change?
Most home and mobile connections get a dynamic IP from the ISP's pool, which can change when the router restarts or the lease expires. A static IP that never changes is usually a paid add-on.
Does every device have its own IP?
Every device has its own private IP on your home network. They all share one public IP on the internet through the router (NAT). With IPv6, each device can also have its own public address.