What Is My IP Address and How Does It Work? (Complete Beginner to Advanced Guide)
Most people who search "what is my IP address" just want the number. If that's you, check iptrackertools.com/what-is-my-ip and you'll have it in two seconds. For the practical side, what your IP is used for day to day, see What Is My IP Address? A Complete Beginner's Guide
This guide is for the next question: how does any of this actually work? How does a number get assigned to your device, how does it get you to the right website, and what happens to it along the way? We'll go from the basics up to the parts most articles skip.
The Basic Idea: Addressing, Not Naming
Every device connected to a network needs a way to be found. An IP address does that job, the same way a street address lets mail find a specific house instead of just a city.
Two versions exist today. IPv4 addresses look like 203.0.113.45. IPv6 addresses look like 2001:0db8:85a3::8a2e:0370:7334. Both point to a specific device, but they were built decades apart to solve the same problem at different scales.
How You Get Assigned an Address
You don't pick your IP address. It's handed to you, and the process depends on where you are in the chain.
At home, your internet provider assigns your router a public IP address. Your router then hands out private addresses to every device connected to it, your laptop, your phone, your smart TV, using a system called DHCP, which automatically leases out addresses so nobody has to configure them by hand.
On the wider internet, address blocks are handed down from a global authority (IANA) to regional registries, then to internet providers, who assign smaller pieces to individual customers and businesses. It's a hierarchy, not a free-for-all, which is exactly why two devices almost never end up with the same public address at the same time.
Why You Have More Than One IP Address
You don't have one IP address. You have at least two, doing different jobs: a public one your provider assigns, and a private one your router assigns to each device on your network. For the full breakdown of how those two differ, see What Is My Public IP Address vs Private IP Address?
What's worth explaining here instead is how one public address can cover an entire household of devices. A process called NAT, short for Network Address Translation, is what makes this work. Your router keeps track of which private device asked for what, then translates traffic back and forth between your private addresses and your one shared public address. Without NAT, every device in every home would need its own public IP, and the internet would have run out of addresses years ago.
How Your IP Address Actually Gets You to a Website
Here's the part most explanations skip entirely: what happens between typing a web address and the page loading.
- DNS lookup. Your browser doesn't know what "example.com" means in address terms, so it asks a DNS server to translate the name into an IP address.
- Routing. Your request leaves your device and passes through a series of routers, each one forwarding it a step closer to the destination, based on routing tables that constantly track the best available paths.
- Connection. Once your request reaches the destination server's IP address, a connection opens, and the server sends data back the same way, hop by hop, until it lands back on your device. None of this happens over a single straight line. Data usually crosses several networks operated by different companies, and the exact path can change from one request to the next depending on network conditions.
IPv4 vs. IPv6: Why Two Systems Exist
IPv4 was built in the early 1980s with room for about 4.3 billion addresses. That sounded limitless at the time. It wasn't, the world now has far more connected devices than that number allows.
IPv6 was designed to fix this permanently, with a pool of addresses so large it's not a practical concern for the foreseeable future. The tradeoff is that IPv6 addresses are longer and harder to read at a glance, and adoption has been slow because IPv4 and IPv6 don't talk to each other directly.
That's why most devices today run what's called dual-stack: they hold both an IPv4 and an IPv6 address at once, and use whichever one the site or service they're connecting to actually supports.
Static vs. Dynamic: Why Your Address Sometimes Changes
Most home connections use dynamic addressing, meaning your provider can reassign your public IP address periodically, often when you restart your router, or sometimes just on their own schedule. A static IP stays fixed permanently, which is why businesses running their own mail or web servers usually pay for one. For the full comparison and who actually needs a static IP, see Static vs. Dynamic IP: What Your ISP Actually Gives You
What Your IP Address Can and Can't Reveal
An IP address can point to your general region and which provider you use, but it can't reveal your exact street address, your name, or anything that specific. It's a network identifier, not a personal record. For the full breakdown of what it does and doesn't expose, see the privacy section in What Is My IP Address? A Complete Beginner's Guide
Quick Answers
Does my IP address change every time I restart my router? Often, yes, if your connection uses dynamic addressing, which most home connections do. It's not guaranteed on every restart, but it's common enough that you shouldn't rely on your address staying the same.
Can two people on different networks have the same public IP address? Not at the same moment, within the same address family. Public IPv4 addresses are allocated to avoid duplication. Private addresses, on the other hand, repeat constantly across different networks, since 192.168.1.1 means something different on every router.
Why does my phone show a different IP address on Wi-Fi versus mobile data? Because it's connecting through two entirely different networks, your home router versus your mobile carrier's network, each with its own address assignment.
Is IPv6 replacing IPv4 completely? Eventually, but not soon. The two are running in parallel right now, and most devices support both so they can reach whichever type of address a given service uses.
The Short Version
Your IP address isn't just a number, it's the result of a hierarchy of assignment, a translation system (NAT) working behind the scenes, and a routing process that moves your data across networks you'll never see. If you just need your number, check it here. If you wanted to understand what's actually happening underneath it, that's what's above.