Every time your phone or computer connects to the internet, it's given a unique numeric label called an IP address (Internet Protocol address). It does exactly what a postal address does for your house: it tells every other device on the internet exactly where to send data so it reaches you.
Without an IP address, no website would know where to send your search results, and no server would know which device to answer. This guide explains what an IP address looks like, the different types, how your device gets one, what it reveals about you and how to look yours up.
What does an IP address actually look like?
The most common type you deal with today is IPv4, written as four numbers between 0 and 255 separated by dots, for example:
203.0.113.42Each of the four numbers is one byte, so an IPv4 address is 32 bits long and there are about 4.3 billion of them — not enough for every device today. A newer version called IPv6 also exists, covering a vastly larger address space and written as groups of hexadecimal numbers and letters separated by colons, such as 2001:db8::1. We cover the differences in full in IPv4 vs IPv6.
An IP address usually comes with companions: a subnet mask that says which part of the number is the network and which part is the device (subnet masks and CIDR), a default gateway that is the way out to the internet, and DNS servers that turn names into addresses (what DNS is).
What does an IP address do?
An IP address has two jobs: it identifies a network interface and it says where that interface is, so routers can forward data towards it. When you open a page, your request travels as small packets: from your device to the router, to your ISP, across several networks, to the server. Each packet carries your address as the sender and the server's address as the destination, and the reply uses them in reverse. You can watch this path yourself with ping and traceroute.
Types of IP addresses
| Type | What it means | Read more |
|---|---|---|
| Public | Routable on the internet; shared by your whole home connection | Private vs public |
| Private | Used only inside a local network, e.g. 192.168.1.20 | Private vs public |
| Dynamic | Assigned temporarily and may change | Static vs dynamic |
| Static | Fixed permanently, used by servers | Getting a static IP |
| IPv4 / IPv6 | The two address formats | IPv4 vs IPv6 |
These categories overlap: your phone's Wi-Fi address is private and dynamic, while a website's server usually has a public, static, IPv4 and IPv6 address.
Where does your IP address come from?
When you connect to the internet — over mobile data, home Wi-Fi, or at the office — your internet service provider (ISP) assigns your connection a public IP address. That's the address every website you visit actually sees. Meanwhile, every device inside your home or office network (router, laptop, printer) also has a private IP address that only means something inside that local network. We explain the difference in Private vs Public IP.
Inside a network, addresses are handed out automatically by DHCP, in four steps often remembered as DORA:
- Discover: a new device shouts "is there a DHCP server?"
- Offer: the router offers an address, e.g.
192.168.1.23, with a lease time. - Request: the device says "yes, I'll take that one."
- Acknowledge: the router confirms, and the device is online.
When this fails you get an address starting with 169.254, which means "no answer from DHCP" (see the Windows guide for fixes).
At the top of the hierarchy, a central registry hands large blocks to five regional registries, which allocate them to ISPs and big organisations, which in turn assign addresses to customers. Each block is recorded together with the organisation that holds it and its network number (ASN).
Does your IP address ever change?
Not necessarily. Most ISPs assign IP addresses dynamically, meaning yours might change when you restart your router or after a few days. Some services and servers instead use a static IP that never changes. On mobile data, many customers also share one address through CGNAT, which is why mobile IPs change often. The full breakdown is in Static vs Dynamic IP, and the methods for getting a new one are in how to change your IP address.
What does an IP address reveal about you?
Blocks of IP addresses are allocated to ISPs and regions and recorded in public databases. That's how a service like this one can estimate your country, city, and ISP from your IP address with reasonably good accuracy — though not GPS-level precision, and sometimes the wrong city (why). It does not reveal your name or street address, which only your ISP can connect to your account; read what an IP can and cannot reveal. If you want to mask it, see how to hide your IP.
How do I check my current IP address?
The simplest way is to open the Show-IP.ir homepage — your public IP address, country, city, ISP, and even connection security status show up instantly, no installation required. It always shows the address of the connection you are using right now. From a terminal, curl show-ip.ir prints just the address.
If you're on a specific operating system and want to see your local (in-network) IP too, check the platform-specific guide: Windows, Mac, Linux, Android, and iPhone. To open your router's settings, which sit at a private address, use the router login guide.
Frequently asked
Is an IP address the same as a MAC address?
No. A MAC address is a hardware identifier that stays within the local network; an IP address is a logical address used to route data across networks. They work together; see IP vs MAC address.
Can two devices have the same IP address?
Not on the same network at the same time; that causes a conflict. Different networks can reuse the same private addresses, and many devices can share one public address through NAT.
Is it dangerous to share my IP address?
Normally no. Websites you visit already see it. It becomes a concern only in specific cases, such as an attacker targeting a game or a stream, where a VPN helps.
Key takeaways
- An IP address is the numeric identifier for any device on the internet — it works like a postal address for data.
- There are two main versions: IPv4 (still the most common) and IPv6 (the newer generation with a much larger address space).
- Every device has both a private IP address (inside its local network) and a public IP address (visible to the internet).
- An IP address can be static or dynamic, depending on the ISP's or server's configuration, and is usually given out automatically by DHCP.
- It reveals your country, ISP and rough area, not your name or exact address.
- Checking your current IP address takes seconds — just open the homepage.