Your IP address changes when your internet service provider assigns you a new one, which usually happens when you restart your modem or router, or when your lease period expires

Most home internet users have a dynamic IP address, meaning it is not permanent. Your internet service provider (ISP) loans you an address for a set period — typically anywhere from a few hours to several months. When that lease ends, or when you power cycle your modem, the ISP assigns you a different address from its available pool. You will not see a notification when this happens; it occurs silently in the background.

A smaller number of users pay extra for a static IP address, which remains the same indefinitely. These are common for businesses that run servers or need consistent remote access, but most residential customers use dynamic addresses because they are cheaper and require no special setup.

The difference matters if you run a home server, use port forwarding, or need others to reach your computer at a fixed address. If your IP changes unexpectedly, those connections break until you update them to the new address.

Key Takeaways

  • Dynamic IP addresses change automatically when your modem restarts or when your lease period expires, which can happen every few hours to several months depending on your ISP.
  • Restarting your modem is the most common reason for an IP change, and it happens whether you restart intentionally or lose power.
  • You can check your current IP address by searching "what is my IP" in any browser, and comparing it to a previous screenshot or note tells you whether it has changed.
  • Static IP addresses stay the same but cost extra and are mainly useful if you run a server, use port forwarding, or need consistent remote access to your home network.
  • If your IP changes and breaks a service you rely on, contact your ISP to ask about static IP options or check whether your service has a dynamic DNS feature.

What triggers an IP address change

Restarting your modem is the single most common trigger. When you power it off and back on, it reconnects to your ISP and requests a new address. This happens whether you restart intentionally (to fix a connection problem) or accidentally (a power outage, unplugging the cable, or a power surge).

The second trigger is time. Your ISP assigns each address a DHCP lease — a countdown timer that ranges from hours to months depending on the provider. When the timer runs out, the ISP reclaims the address and assigns you a new one the next time your modem checks in. You do not have to do anything; it happens automatically.

A third, less common trigger is ISP maintenance or network changes on their end. If your ISP reconfigures its network or experiences an outage, you may receive a new address when service restores.

How to check if your IP address has changed

Open any web browser and search for "what is my IP" or "my IP address". The search results will display your current IP address — a string of four numbers separated by periods, like 192.168.1.5 for a local network address or 203.0.113.42 for your public address. Write it down or take a screenshot.

To know whether it has changed, you need a previous record. If you noted your IP address a week ago and it is different now, it has changed. If you have no previous record, you can check your router's admin panel. Log into your router (usually by typing 192.168.1.1 or 192.168.0.1 into your browser address bar, then entering your router password) and look for the WAN IP or Public IP section. Some routers also show the DHCP lease time remaining, which tells you when the next automatic change might occur.

Your ISP can also tell you your current address. Call their support line or log into your account on their website, and they can confirm what address they have assigned to your account.

The difference between dynamic and static IP addresses

A dynamic IP address is temporary and changes on a schedule set by your ISP. It is the default for most home internet customers because it is cheaper and requires no extra setup. The ISP maintains a pool of addresses and loans them out as needed, then recycles them when leases expire. This system works well for everyday browsing, email, and streaming because you do not need a permanent address.

A static IP address is permanent and does not change unless you request it. You pay a monthly fee (typically $10 to $20 extra) to reserve one address just for your account. Static IPs are useful if you run a web server, host a game server, use port forwarding to access your home network remotely, or need others to reach you at a fixed address. Without a static IP, those services break every time your address changes.

Some ISPs offer static IPs only to business customers, while others sell them to residential users. Contact your ISP to ask whether they offer static IP service and what it costs.

Why your IP address changing might cause problems

If you use port forwarding — a router setting that directs traffic from the internet to a specific device on your home network — a changing IP address breaks the connection. The port forward points to your old address, and when you get a new one, incoming traffic no longer reaches the right place. You have to update the port forward rule to the new address.

If you run a home server or host a game server, others connect to you using your IP address. When it changes, they can no longer reach you until you tell them the new address. This is why game server hosts and home server operators almost always use static IPs.

If you use remote access software like TeamViewer or AnyDesk to reach your home computer from elsewhere, the software usually handles IP changes automatically because it uses a cloud relay. However, if you set up direct IP-based access, a changing address will break it.

For most people — those who just browse the web, check email, and stream video — a changing IP address causes no problems at all. You will never notice it happened.

How to prevent your IP address from changing

The most reliable way is to pay your ISP for a static IP address. This removes the automatic change entirely. Contact your ISP's sales or support team, ask about static IP availability and pricing, and request it be added to your account. Setup usually takes one business day.

A second option is dynamic DNS, a service that automatically updates a domain name to point to your current IP address whenever it changes. You register a domain (or use a free subdomain from a dynamic DNS provider like No-IP or DuckDNS), install a small client on your computer or router, and the client reports your IP to the service every few minutes. Others can then reach you using the domain name instead of the IP address, and the domain automatically stays current even as your IP changes. This is free or very cheap and works well for remote access and home servers.

A third option is to configure your router to request the same IP address every time it connects. This is called a DHCP reservation or sticky DHCP. Log into your router's admin panel, find the DHCP settings, and look for an option to reserve an address for your modem's MAC address. The ISP will usually grant the same address repeatedly, though it is not may provide — the ISP can still assign a different one if the reserved address is no longer available. This is less reliable than a true static IP but costs nothing.

How often IP addresses typically change

The frequency depends entirely on your ISP's DHCP lease time. Some ISPs set leases for 24 hours, meaning your address changes once per day. Others use 7-day leases, 30-day leases, or even longer. A few ISPs use very short leases of just a few hours. You can find your lease time by logging into your router and checking the DHCP settings, or by calling your ISP and asking.

In practice, many users keep the same address for weeks or months even with a dynamic setup, because the ISP often reassigns the same address to the same modem when the lease renews. However, you cannot count on this. Any restart of your modem can trigger a new address, and you should assume it will change at some point.

Frequently Asked Questions

Can someone track me using my IP address?

Your public IP address can be used to determine your approximate location (usually your city or region, not your exact street) and your ISP. It cannot identify you personally unless someone subpoenas your ISP for account information. A VPN masks your IP address by routing your traffic through another server, making it appear as though you are in a different location. This is useful for privacy, but a changing IP address alone does not protect you.

Does restarting my router change my IP address?

Usually yes. When you restart your router or modem, it disconnects from your ISP and reconnects, which triggers a new IP address request. However, the ISP often assigns you the same address again if the lease has not expired. You cannot predict whether you will get the same address or a new one without checking.

What if I need my IP address to stay the same for work?

Contact your ISP and request a static IP address. If they do not offer it or it is too expensive, set up dynamic DNS using a service like No-IP or DuckDNS. This lets others reach you using a domain name that automatically updates whenever your IP changes, so they do not need to know your current address.

Is my local IP address the same as my public IP address?

No. Your local IP address (like 192.168.1.5) is used only within your home network and is assigned by your router. Your public IP address (like 203.0.113.42) is assigned by your ISP and is what the internet sees. When you search "what is my IP", you get your public address. Only your public address changes based on ISP assignments; your local address is controlled by your router.

Will changing my IP address affect my internet speed?

No. Your speed is determined by your ISP plan and connection quality, not by your IP address. A new IP address does not make your connection faster or slower.