IP Address
BeginnerThe numeric label that identifies a device on a network — the internet's return address, and the single most-tracked identifier in online privacy.
In depth
An IP address (Internet Protocol address) is the numeric identifier assigned to every device that communicates on a network. It serves two roles at once: it names the device and locates it, so responses can find their way back. Everything in the proxy and VPN world ultimately revolves around controlling which IP address a website sees.
IPv4 and IPv6
- IPv4 — the classic format (
203.0.113.42), about 4.3 billion possible addresses. Exhaustion made IPv4 addresses a scarce, traded commodity, which is why IPv4 proxies cost real money. - IPv6 — the successor (
2001:db8::1), with an effectively unlimited supply. Abundant and cheap, but not universally supported by websites.
What your IP reveals
An IP alone doesn't name you, but it leaks a surprising amount: your approximate location (usually city-level), your ISP, whether the address belongs to a home, business, datacenter, or mobile carrier, and — through reputation databases — its history of abuse. Websites combine these signals to decide how much to trust a visitor before a single page loads. Static IPs stay with you for months; dynamic IPs rotate at the ISP's whim, which is typical for home connections.
Why proxies exist
You cannot change what your IP reveals — but you can borrow a different one. Proxies, VPNs, and Tor all work by substituting another IP's identity and reputation for your own.
Examples
- A website maps a visitor's IP to Amsterdam and switches its interface to Dutch.
- An ISP assigns a home router a dynamic IP that changes after a modem reboot.
- A fraud system flags a login because the account's usual residential IP was suddenly replaced by a datacenter address.
Common use cases
FAQs
Not precisely — an IP typically resolves to a city and an ISP, not a street address. Identifying an individual requires the ISP's subscriber records, which are only released through legal process. Still, combined with other data, IPs meaningfully narrow down who you are.
A static IP stays assigned to you indefinitely; a dynamic IP is leased temporarily and changes periodically. Homes usually get dynamic IPs, servers get static ones. For proxy work, static IPs suit long-lived accounts while dynamic behavior underpins rotation.
It removes one identifier, not all of them. Websites also track cookies and browser fingerprints, which survive IP changes. Real anonymity work pairs IP substitution with fingerprint and cookie management so every layer tells the same story.