What is my public IP?
One public address serves your whole household or office. Your laptop, your phone and the smart speaker all appear to the internet as the address above, because your router translates between them and the outside world. That is why a site cannot tell your devices apart by IP alone, and why a household shares a reputation.
Your public IP address, the one the outside internet sees, is shown above. It is assigned to your connection by your internet provider and is shared by every device behind your router. It is what distinguishes your network from every other network online.
The word public is the key distinction. Inside your home or office you also have private IP addresses (things like 192.168.x.x) that your router hands out to each device. Those never travel across the internet. Your public IP is the single face your whole network shows to the world.
This is the address that appears in server logs, that geolocation services use to guess your city, and that a VPN changes when you want to appear somewhere else.
How a website reads this
This is the exact call a page makes. Nothing else is involved, and nothing is sent anywhere: the value is read in your browser and displayed to you.
fetch('/api/ip')Identical mechanism to the IP address page. The word public matters: this is the address your router presents to the internet, shared by every device behind it, and it is the only one a website can see without your help.
- Needs your permission
- No, it is read silently
- Can it be faked
- Partly. Changed by routing, not by editing. A VPN substitutes its own exit address; a router reboot may earn you a new one from your provider.
- Contribution to a fingerprint
- Not counted. Not part of the fingerprint estimate, same reasoning as the IP address page. How we estimate this.
One address, every device: how NAT works
Your router keeps a translation table. That table is the entire reason a household with a dozen devices needs only one public address.
| Step | What happens | What the website sees |
|---|---|---|
| Your laptop opens a page | It sends the request from its private address, say 192.168.1.24, to your router. | Nothing yet. |
| The router rewrites it | It swaps the private source address for its own public one, and notes which internal device and port the reply belongs to. | A request from your public address. |
| The site replies | The response comes back to the public address, to the port the router chose. | It replies to one address and knows nothing more. |
| The router delivers it | It looks the port up in its table and forwards the response to your laptop, not to your phone. | Still nothing. The split happens entirely inside your network. |
This is why every device in your house shares one public address, why a site cannot tell your laptop from your phone by IP, and why blocking an address blocks a household rather than a person.
Why everyone in your house shares one public IP
There were never enough IPv4 addresses to give one to every device, so network address translation was invented to share them. Your provider gives your router a single public address and your router hands out private ones internally, keeping a table of which internal connection maps to which outgoing port.
The consequences show up constantly once you know to look for them. A rate limit applied per IP throttles your whole household. A ban applied to an address bans everyone behind it. A site that says you have already used your free trial may be looking at your flatmate. And services that need an incoming connection, such as hosting a game server, need port forwarding precisely because the router has no idea which internal device an unsolicited packet is for.
Mobile networks push this further with carrier-grade NAT, where thousands of subscribers share one public address. On such a connection your public IP identifies a carrier region and nothing more.
Does my public IP change, and can I change it?
Most consumer connections use a dynamic address, leased from the provider and renewed periodically. In practice it can stay the same for months and then change without notice, typically after an outage, a long disconnection or a router reboot. Business lines often pay for a static address precisely because services that depend on a fixed address need one.
You can influence it but not choose it. Disconnecting for long enough to drop the lease sometimes earns you a new address. A VPN replaces the address sites see wholesale, which is a routing change rather than a change to your connection. Nothing you do in your browser affects it at all: this is a property of your connection, not of your software.
What you should know
Why sites collect it
Any server you contact must know your public IP to send data back. Sites additionally use it for coarse geolocation, regional content rules, abuse prevention and security logging.
Privacy implications
Your public IP ties your activity to your provider and rough location and is logged nearly everywhere. It is not your identity, but with cooperation from a provider it can be linked to an account, which is why privacy-focused users route around it.
How to change or hide it
Use a VPN or Tor to present a different public IP. On a dynamic connection, a router restart may change it. On a static connection it stays fixed until your provider changes it.
Frequently asked questions
What is the difference between public and private IP?
Your public IP is visible to the whole internet and shared by your network; your private IP is assigned by your router and only used inside your own network.
Does everyone in my house have the same public IP?
Usually yes. All your devices share one public IP through your router, while each has its own private IP internally.
Sources
Browser behaviour changes and vendors cap these values differently, so the claims above that are not self-evident are checked against the specifications and vendor documentation below.
Last checked on . How these values are measured and estimated is set out on the methodology page.
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