An IP address (Internet Protocol address) is a number that identifies a device or connection on a network so that data knows where to go. Think of it as the return address on a letter: when your browser asks a website for a page, the website needs somewhere to send the answer.
How IP addresses work
Every device that talks over the internet needs an address. At home, your router gets one public address from your internet provider, and your phone, laptop and TV each get a private address from the router. Websites only see the public one, which is why everyone in a household appears to come from the same address. The difference is explained in public vs private IP addresses.
There are two versions in use. IPv4 addresses look like 203.0.113.7. IPv6 addresses look like 2001:db8:85a3::8a2e:370:7334 and exist because IPv4 ran out of room. Read IPv4 vs IPv6 for the details.
Who assigns your IP address?
Your internet service provider (ISP) or mobile carrier. It owns blocks of addresses and hands one to your connection, sometimes the same one for months, sometimes a different one each time your router restarts. See static vs dynamic IP addresses.
What can a website learn from your IP address?
- Your approximate location. Usually country and region, often the city. Databases map address blocks to places, and they are estimates.
- Your internet provider and whether you are on a home, mobile, corporate or data-centre network.
- Whether you look like a VPN or proxy. Try the VPN check.
- A way to recognise you across visits and sites, especially when combined with cookies or a browser fingerprint.
What an IP address does not reveal
A website cannot get your name, your street address, your phone number or the contents of your device from your IP address. Your internet provider can link an address to a customer account, but it hands that information to others only through legal processes. The popular idea that someone can "hack you with your IP address" is mostly myth: an address is not a login. The realistic risks are tracking, location inference, and attacks on services you have left exposed (see the open port checker).
Should you worry about your IP address?
For most people it is a modest privacy concern rather than a security emergency. If you want to limit what sites learn, read how to hide your IP address. If you only want to know what yours is, it is at the top of the home page.