What does a website know about my connection?
Your connection tells a server which address to reply to, and that address carries a provider and a rough region with it. What it does not carry is your name, your street or anything about which device behind that address made the request. Those are inferences other people sell, not facts your browser gave away.
Network
What your connection reveals, from your public IP to your headers.Every network signal, with the call behind it
8 signals, none of which ask your permission first. The entropy column is this site's own estimate of how much each signal narrows a crowd, not a measured population statistic; the methodology page explains why that distinction matters.
| Signal | JavaScript call | Permission | Entropy (bits, estimated) | Fakeable |
|---|---|---|---|---|
| IP address | fetch('/api/ip') | None | not counted | Partly |
| IPv4 address | fetch('/api/ip') then check for ':' in the address | None | not counted | Partly |
| Public IP | fetch('/api/ip') | None | not counted | Partly |
| Private IP | not readable by a website | None | not counted | No |
| IP location | fetch('/api/ip') returning the platform's geo headers | None | not counted | Partly |
| Connection type | navigator.connection | None | 1.5 | Partly |
| Request headers | reconstructed from navigator, not read directly | None | not counted | Yes |
| Referrer | document.referrer | None | not counted | Yes |
Why none of this comes from a JavaScript API
Every other category on this site is read with a call in the page. The network category is not, and cannot be. There is no navigator.ipAddress, because your browser does not know your public address: it hands packets to your router, and your router talks to the internet.
The only way a page can show you your address is to make a request and have the other end report back where it arrived from. On this site that other end is our own endpoint, which echoes the address and writes nothing down. Every what-is-my-ip tool on the web works this way, whether it says so or not.
The same applies to your request headers. JavaScript cannot read the headers its own document was fetched with, so the header card is reconstructed from the JavaScript equivalents. It is close, but it is not the server's view: the server also sees your cookies, your accepted encodings and anything a proxy or extension added along the way.
What an IP address does and does not prove
It reliably identifies your internet provider, and through the provider, a country. That much is solid. City level accuracy is a different matter: the databases map a provider's equipment rather than a person, so a fixed line in a small town is often placed in the nearest large one, and a mobile connection can be placed in another region entirely.
It identifies a household or an office, not a person. One public address serves every device behind the router, which is why a site cannot tell your laptop from your phone by IP, and why reputation attaches to a household rather than to you.
It is also not fixed. Consumer connections are commonly reassigned, mobile addresses change as you move between towers, and any VPN or proxy substitutes its own exit address wholesale. An IP is a good short-term handle and a poor long-term identity, which is exactly why fingerprinting exists.
The private address is the one nobody can take
The most common misunderstanding in this category is between the public address your router presents to the internet and the private one it hands your laptop, typically starting 192.168 or 10. The private one is defined in RFC 1918 and it is meaningless outside your own network.
Websites used to be able to read it anyway, through a side effect of the WebRTC connection setup. Browsers closed that hole by substituting randomised mDNS hostnames for real local addresses. The card on this site is therefore blank on purpose, and a blank card is the correct answer rather than a broken one.
Frequently asked questions
Can a website find my home address from my IP?
No. It gets your provider and an approximate area, usually accurate to the country and roughly accurate to the city. Linking an address to a subscriber requires records held by the provider, which are released to law enforcement under legal process and not to websites.
Why does my IP location say the wrong city?
Because the lookup maps your provider's network equipment rather than you. Traffic can be routed through a hub in another city, and on mobile networks the address often belongs to a regional gateway. Country is usually right, city frequently is not.
Does everyone in my house share the same public IP?
Yes, in almost every home setup. Your router performs network address translation, so every device behind it appears to the internet as one address. That is also why a site cannot separate your devices by IP alone.