Why Your IP Address Keeps Changing, and Why That’s Usually Normal

September 28, 2026

Home internet users who check their IP address often find the number has changed overnight. Experts say this is by design, not a sign that anything is wrong.

Modern home Wi-Fi router with several antennas — A residential router usually borrows its public IP address from the internet provider for a limited period.

Millions of households share a small puzzle: the IP address shown by “what is my IP” websites changes from week to week, sometimes day to day. For most people it goes unnoticed. For gamers hosting servers, remote workers, and anyone running a home security camera, a changing address can break connections without warning.

The explanation starts with scarcity. The original internet addressing system, IPv4, has about 4.3 billion possible addresses, and they ran out years ago in most regions. Internet service providers have far more customers than addresses to give each one a permanent number, so they share them.

Borrowed, Not Owned

Most residential connections get what is called a dynamic IP address. It is assigned by DHCP, or Dynamic Host Configuration Protocol, which lends an address to your router for a set period known as a lease. When the lease nears its end, the router asks to renew it. Often it gets the same address back, but not always.

A power outage or router restart, leaving a modem unplugged, maintenance on the provider’s network, an expired lease, or replacing the router or modem can all trigger a new address.

Rows of network switches connected by blue and yellow cables — Internet providers continually route and reassign a limited pool of IPv4 addresses across their networks.

Mobile and Shared Addresses

Phones on cellular networks change addresses even more often. Carriers commonly use carrier-grade NAT, or CGNAT, which places many customers behind a single shared public address. Moving between towers, switching from Wi-Fi to mobile data, or toggling airplane mode can all produce a new one. Some home providers now use CGNAT as well.

Virtual private networks add another layer. With a VPN turned on, websites see the VPN provider’s address rather than the user’s, and it may change every time the user reconnects.

Smartphone held near a cellular tower at sunset — Cellular connections can receive a new address as a phone moves between towers or switches networks.

Laptop showing a secure network connection graphic — A VPN replaces the address visible to websites with one belonging to the VPN service.

Two Kinds of Addresses

The address on “what is my IP” sites is the public one, visible to the internet. Inside the home, the router gives each device a private address, often starting with 192.168 or 10. These can also change as devices connect and disconnect, which sometimes confuses printers and smart-home gadgets.

Is It a Security Risk?

Generally, no. A changing public address is routine and does not mean an account or device has been compromised. Some privacy advocates see it as a modest benefit, since it makes long-term tracking by IP address slightly harder.

What Users Can Do

For those who need a stable address, there are several options:

Static IP: Many internet providers offer one, usually for an extra monthly fee and mostly on business plans.
Dynamic DNS: Services link a fixed hostname to a changing address and update it automatically.
DHCP reservation: A router setting keeps a device’s private address the same inside the home.

Home security camera viewed remotely on a smartphone — Dynamic DNS can keep cameras and other home services reachable after a public IP address changes.

The Long-Term Fix: IPv6

The address shortage behind most of these changes has a successor already in place. IPv6 uses 128-bit addresses instead of IPv4’s 32-bit ones. That works out to roughly 340 undecillion possible addresses, enough to give every device on Earth its own unique public address many times over.

IPv6 addresses look different, too. Instead of four short numbers separated by dots, they are written as eight groups of hexadecimal characters separated by colons. Runs of zeros can be shortened, so many addresses appear more compact in practice.

With so many addresses available, a household typically receives an entire block called a prefix, and each device can have its own public address. That removes much of the need for NAT and CGNAT, simplifying gaming, video calls, and remote access.

It does not mean addresses stop changing. Some providers still rotate a home’s prefix, and most phones and computers use privacy extensions that deliberately generate temporary IPv6 addresses. Users who need stability may still need a static prefix or dynamic DNS.

Adoption has been gradual. Most major providers, mobile carriers, and large websites now support IPv6, but many networks and older devices still depend on IPv4. Because the two systems are not directly compatible, most networks run both side by side in a setup known as dual stack.

Users can check whether their connection supports IPv6 at test-ipv6.com. Until the transition is complete, IPv4’s borrowed and shared addresses will remain part of daily internet life, and the number on a “what is my IP” page will keep changing from time to time.