Your IP address usually changes every time you restart your modem, which for most home users means days to weeks between changes
How often your IP address changes depends on your internet service provider (ISP) and the type of connection you have. For residential broadband users, the most common scenario is that your dynamic IP address stays the same until you restart your modem or router, or until your ISP's lease period expires — typically between 24 hours and 30 days. If you restart your modem weekly, your IP might change weekly. If you never restart it, your IP could stay the same for months.
Business accounts and users with static IP addresses work differently. A static IP does not change unless you request it or cancel your service. Static IPs cost extra and are usually purchased by people who run servers, host websites, or need a consistent address for security systems or remote access.
Mobile devices on cellular networks change IP addresses constantly — sometimes multiple times per day — because cell towers assign new addresses as you move between coverage areas. On Wi-Fi, your IP address is the same as your modem's, so it changes on the same schedule.
Key Takeaways
- Most home internet users have dynamic IP addresses that change when the modem restarts or the lease expires, typically within days to weeks.
- Restarting your modem is the most common reason your IP address changes, and it happens when ready after the restart completes.
- Static IP addresses do not change unless you request a change or cancel service, and they cost extra from your ISP.
- Mobile devices on cellular networks change IP addresses frequently as they move between towers, while Wi-Fi devices use the modem's IP address.
- Your ISP controls the lease period for dynamic IPs, which ranges from 24 hours to 30 days depending on the provider.
Why ISPs use dynamic IP addresses instead of static ones
Internet service providers use dynamic IP addresses because there are not enough IP addresses for every device to have a permanent one. A dynamic address is leased to you for a set time, then returned to the pool when the lease expires so another customer can use it. This system lets ISPs serve more customers with fewer addresses.
Dynamic addressing also gives ISPs a way to manage network traffic and security. If a customer's connection is compromised or used for spam, the ISP can force a new IP address by shortening the lease or resetting the connection. Static IPs, by contrast, stay with one customer indefinitely, which makes them easier to track and target but also more stable for services that need a consistent address.
What happens when your modem restarts
When you restart your modem — either by unplugging it, pressing the reset button, or through your ISP's app — the modem disconnects from your ISP's network and reconnects. During reconnection, the ISP's server assigns your modem a new IP address from its available pool. This usually takes 30 seconds to 2 minutes.
Your old IP address goes back into the pool and may be assigned to another customer. The new IP is typically different from the old one, though occasionally you might get the same address again if the pool is small or the timing aligns. Devices on your home network (phones, computers, printers) keep their local addresses on your home network, but their external IP — the one the internet sees — changes with the modem.
How lease expiration works
Your ISP assigns your modem an IP address with an expiration date called the DHCP lease period. Common lease periods are 24 hours, 7 days, 14 days, or 30 days, depending on your ISP. When the lease is about to expire, your modem automatically requests a renewal from the ISP. If the ISP grants the renewal, your IP stays the same. If not, you get a new one.
In practice, most ISPs renew the lease automatically if your modem is still connected and in good standing. Your IP address usually only changes due to lease expiration if you have been offline for a while, your account has a service interruption, or your ISP is doing network maintenance. For most users, restarting the modem is a more common reason for an IP change than waiting for the lease to expire.
How to check your current IP address
You can find your external IP address — the one the internet sees — by visiting a website like whatismyipaddress.com or iplocation.net. These sites display your IP when ready and usually also show your approximate location and ISP name.
To find your modem's local IP address (the address it uses on your home network), open a web browser and type 192.168.1.1 or 192.168.0.1. This takes you to your modem's settings page, where you can see the IP address assigned to the modem itself. Different modem brands use different default addresses, so check your modem's manual if neither of those works.
When you might want a static IP address
A static IP is useful if you run a home server, host a website, use remote desktop software to access your computer from elsewhere, or have security cameras that need a consistent address. It is also helpful if you use a VPN or need to whitelist your IP address with a bank or service provider.
Static IPs typically cost $5 to $15 per month from your ISP, depending on the provider. You request one through your ISP's website or by calling customer service. Once activated, your IP address stays the same until you cancel the service or request a change. Some ISPs offer static IPs only to business customers, so check with your provider about availability.
IP address changes on mobile and public Wi-Fi
Mobile devices on cellular networks get a new IP address from your carrier's network, not from your home modem. These addresses change frequently — sometimes every few minutes — as your phone moves between cell towers and your carrier reassigns addresses. You do not control this process, and it happens automatically in the background.
When you connect to public Wi-Fi at a coffee shop or library, your device uses the IP address of that location's modem or router. If you move to a different Wi-Fi network, you get a new IP address. If you stay on the same Wi-Fi network, your IP stays the same as long as you remain connected, though the network operator may change it if you disconnect and reconnect.
Frequently Asked Questions
Can I prevent my IP address from changing?
You can prevent changes by purchasing a static IP from your ISP, which costs extra and requires a request to your provider. For a dynamic IP, you can avoid changes by never restarting your modem and keeping it powered on continuously. However, your ISP may still change your IP during maintenance or if your lease expires, depending on their policies.
Does changing my IP address affect my internet speed?
No. Your IP address is just a label the internet uses to route data to your modem. Changing it does not affect speed, latency, or connection quality. The only time you might notice a brief interruption is during the modem restart itself, which takes a minute or two.
Will websites know if my IP address changes?
Websites can see your IP address when you visit them, and they may notice if it changes between visits. Some sites use this information for security (flagging unusual logins from new IPs) or for tracking user behavior. If you want to hide your IP from websites, you can use a VPN service, which masks your real IP and shows the VPN provider's address instead.
What is the difference between my modem's IP and my computer's IP?
Your modem has an external IP address that the internet sees, and your computer has a local IP address that only your home network sees. When you visit a website, the site sees your modem's external IP, not your computer's local address. Your computer's local IP rarely changes unless you restart your computer or your modem reassigns addresses.
Does my IP address change when I restart my router instead of my modem?
Restarting your router alone usually does not change your IP address, because the router does not connect directly to your ISP — the modem does. Restarting the modem is what triggers a new IP. However, if your modem and router are combined into one device, restarting it will change your IP address.