What Is My IP

An address like 192.168.1.47 is not the address the internet sees. Three ranges are reserved for private networks and are deliberately unroutable in public: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. Every home router on earth uses one of them, which is why millions of houses all have a device at 192.168.1.1 with no conflict.

Your router performs NAT, network address translation. It rewrites the source address of every outbound packet to the one public address your ISP gave it, keeps a table of which internal device asked for what, and unwraps the replies on the way back. So a website can never see 192.168.1.47, and it cannot tell whether the request came from your laptop, your TV or your doorbell. It only sees the one public address, which is the number at the top of this page.

The practical consequence: an IP identifies a household or an office, not a person. If a site bans your IP, it bans everyone on your connection. If your work VPN is on, the address belongs to your employer.

The last blocks were handed out by IANA in 2011 and the regional registries ran dry over the following decade. Two workarounds keep IPv4 alive.

The first is dynamic assignment. Your ISP leases you an address rather than giving you one, and it can change when your router reboots, when the lease expires, or when the ISP reshuffles its network. This is why a firewall rule or a DNS record that hard-codes your home address quietly breaks a month later, and why dynamic DNS services exist.

The second is CGNAT, carrier-grade NAT, and it is why the address above may not really be yours alone. Your ISP performs a second layer of NAT in its own network, so hundreds of subscribers share one public IPv4 address. Mobile networks have done this for years and many fibre and cable ISPs now do it too. Symptoms: port forwarding does nothing, you cannot host a game server, peer-to-peer connections fall back to slow relays, and you occasionally hit a CAPTCHA because a neighbour you have never met misbehaved.

How to tell you are behind CGNAT. Log into your router and look at its WAN address. If it starts with 100.64. through 100.127., the range reserved for exactly this, and does not match the address at the top of this page, you are sharing. A private 10.x WAN address that differs from this page is the same story.

IPv6 is the actual fix. 128-bit addresses give every device a globally routable one, with no NAT required, which restores end-to-end connections. Because a permanent per-device address would be a tracking gift, operating systems generate rotating privacy addresses for outbound traffic, so an IPv6 address changing every day or so is a feature and not a fault.

All of it has to be looked up in a database, which means those pages take your IP address and send it to a third party's API, on every page load, so that you can read a city name you already knew.

We are not doing that for a decoration. Everything above comes out of Cloudflare's answer to the request you already made to our server, so your address does not travel anywhere new. If you do want the ASN and the registry record, look it up yourself with a WHOIS or RDAP query at your regional registry: deliberately, once, knowing where it went, rather than automatically every time you open a tab.

The same restraint applies to what is kept. Beyond the page's own stylesheet and script, this tool makes one network request, the one that reads your address, repeated only when you press Check again, and it writes nothing: no cookie, no localStorage entry, no analytics ping carrying your IP. You can confirm it yourself in your browser's network tab, which is rather the point of saying it.