What is my IP address?
Your IP address is the address of your connection on the internet: every site you open sees it, and it's shown at the top of this page. Your internet provider gives it out, or a proxy or VPN when you use one. By the IP, sites can tell roughly where you are and which provider you're with.
It isn't your computer's address inside your home network, such as 192.168.1.10: sites don't get that one. Most connections have an IPv4 address like 203.0.113.42, and many also have a longer IPv6 one.
What this IP check shows
The IP address sites see when you open them, the city and country it belongs to, and the provider that owns it. Then the page compares that address with what your browser reports: the address WebRTC gives out, your timezone, your languages and the browser itself. When they point to different places or to a different device, sites can tell you are behind a proxy or VPN.
How sites detect a proxy or VPN
Proxy detection usually combines several signs. Sites look the address up in lists of data centers, VPNs and Tor exit nodes, check whether WebRTC shows another address, and whether the proxy names itself in headers such as Via or X-Forwarded-For. Then they compare the browser with the IP: its clock, its languages, and whether the User-Agent fits the system, the fonts and the graphics card.
This page runs the same kinds of checks on the connection you are using right now. Unlike a proxy checker that tests a list of proxies, it shows how your own browser looks to sites.
IP type: home, data center, VPN or Tor
Home and mobile internet providers give out the addresses sites trust most. Data-center addresses belong to hosting companies: many proxies use them, and some sites check them more strictly. The page also looks the address up in public lists of VPN ranges and Tor exit nodes.
WebRTC leak test
WebRTC lets the browser connect directly, for example for video calls. The page asks a public STUN server which address it sees. If that address differs from your IP, WebRTC goes around your proxy, and sites can see the address of your own connection.
Timezone and language
Your browser tells every site its timezone and preferred languages. The page compares your browser's clock with the time where the IP is, and the language of pages with the language your browser sends in requests.
Browser fingerprint test
Screen size, CPU cores, memory, the graphics card, and the way your device draws an image and processes sound make up a browser fingerprint. Sites use it to recognize a device without cookies, and check that its parts fit together: the User-Agent should match Client Hints, the browser engine, the installed fonts, the touch screen and the graphics card.
Extensions that change these values usually do it only in the page. The page compares them with a web worker and a new frame and checks that browser functions are untouched, so such changes show up.
FAQ
Is a data-center IP bad?
Not necessarily. Many proxies use data-center addresses, and most sites work with them. Some sites check them more strictly than home addresses.
Why doesn't my timezone match the IP?
Your computer's clock is set to where you are, while the proxy or VPN is somewhere else. Set the timezone of the IP's location, or use a browser profile with its own timezone.
How do I stop a WebRTC leak?
In Firefox, open about:config and set media.peerconnection.enabled to false. Chrome has no such setting in its menu, but extensions that block WebRTC can do it. In Accovod profiles, WebRTC doesn't reveal your real IP.
Can sites see my real IP through a proxy?
They can if WebRTC gives it out, or if the proxy passes it on in headers such as X-Forwarded-For. This page checks both.
Why does my IP show the wrong city?
Location databases link address ranges to places. They are usually right about the country and less often about the city, and mobile carriers and proxies may use addresses registered in another city.
Does incognito mode hide my IP?
No. A private window doesn't keep history and cookies after you close it, but sites see the same IP as in a normal window. To show sites another IP, you need a proxy, a VPN or another network.
Can I check an IP that isn't mine?
Yes: type it in «Look up another IP». The page shows where the address is, who owns it, its timezone, whether it belongs to a data center and whether it is in VPN or Tor lists. To see what sites get through a proxy, open this page through the proxy: the address sites see can differ from the one you connect to, and the timezone, WebRTC and browser checks need your own connection.