What an IP address is and why you need to know yours

Your Internet Protocol address (IP address) is a number that identifies your device on your home network and on the internet. It looks like four numbers separated by dots — for example, 192.168.1.5 on your home network, or something like 203.45.67.89 when you're looking at the outside world. Knowing your own IP address helps you troubleshoot network problems, set up security rules on your router, and understand what information websites can see about your location.

Every device connected to your network — your computer, phone, printer, smart TV — has its own IP address. Your router assigns these addresses automatically using a system called DHCP. When you're setting up security features like port forwarding or creating a list of devices you trust, you'll need to know which IP address belongs to which device.

Key Takeaways

  • Your local IP address (the one on your home network) starts with 192.168 or 10.0 and is different from your public IP address (the one the internet sees).
  • On Windows, open Command Prompt and type ipconfig; on Mac or Linux, open Terminal and type ifconfig or ip addr.
  • Your router's admin page shows all connected devices and their IP addresses, which is useful for identifying unknown devices on your network.
  • Your public IP address changes periodically unless you pay for a static IP, and websites can see it but not which specific device sent the traffic.

Finding your IP address on Windows

The fastest way on Windows is through Command Prompt. Click the Start button, type cmd, and press Enter. A black window opens. Type ipconfig and press Enter. You'll see a list of network adapters. Look for the one labeled "Ethernet" (if you're plugged in with a cable) or "Wireless LAN adapter" (if you're on Wi-Fi). Next to "IPv4 Address" you'll see your local IP address — the one that matters for your home network.

If you see multiple adapters listed, ignore the ones labeled "Loopback" or "Virtual" — those are for your computer's internal use. The address you want starts with 192.168 or 10.0. Write it down or take a screenshot if you need it for router settings.

Finding your IP address on Mac or Linux

On Mac, open Terminal (find it in Applications > Utilities). Type ifconfig and press Enter. Look for the section labeled "en0" or "en1" (these are your network adapters). Next to "inet" you'll see your local IP address.

On Linux, open a terminal and type ip addr or hostname -I. The output shows all your network adapters and their addresses. Again, you're looking for an address that starts with 192.168 or 10.0.

Checking your IP address through your router

Your router keeps a list of every device connected to it, along with each device's IP address. This is one of the most useful places to look if you're trying to figure out what devices are on your network or if you suspect something unfamiliar has connected.

Open a web browser and type your router's IP address into the address bar. This is usually 192.168.1.1 or 192.168.0.1 — check your router's label or manual if neither works. You'll be asked to log in. Use the username and password printed on your router (often "admin" and "admin", or "admin" and the router's serial number). Once you're in, look for a section called "Connected Devices", "DHCP Clients", or "Device List". You'll see the name of each device, its IP address, and sometimes its MAC address (a longer identifier used for security rules).

Understanding your public IP address

Your public IP address is what the rest of the internet sees when your devices connect outward. It's different from your local IP address. To find it, search "what is my IP" in any search engine, or visit a site like whatismyipaddress.com. The number shown is what websites and online services can see about your location and internet provider.

Your public IP address usually changes every few months when your internet provider reassigns addresses, or when you restart your modem. If you need it to stay the same — for example, if you're setting up a security camera that needs a permanent address — you can contact your internet provider about a static IP, though this usually costs extra per month.

The important thing to know: websites can see your public IP and use it to estimate your general location (usually to the city level, not your street). They cannot see which specific device in your home sent the traffic, because your router handles that translation. This is why a VPN matters if you want to hide your public IP from websites — it replaces your real public IP with the VPN provider's IP.

Why you might need to know your IP address

If you're setting up port forwarding on your router to let a specific device receive traffic from outside your network, you need that device's local IP address. If you're creating a list of trusted devices for your network security, you'll reference IP addresses. If you're troubleshooting a slow connection or a device that won't connect, your router's device list shows you which IP addresses are active and which are stuck or offline.

You also need your IP address if you're setting up a static DHCP assignment — telling your router to always give the same IP to the same device, so security rules don't break when the address changes. This is especially useful for printers, security cameras, or computers you use for specific tasks.

Spotting unfamiliar devices on your network

Your router's device list is your first line of defense against unauthorized access. Log in to your router regularly and look at the connected devices. You should recognize all of them — your laptop, phone, tablet, printer, smart TV, whatever you own. If you see a device with a name you don't recognize, that's a sign something has connected without your permission.

Device names are often generic ("Android-Device" or "Unknown") if the device hasn't been set up yet, or if someone is using default settings. If you see something suspicious, you can disconnect it from your router's admin page — usually by clicking a "disconnect" or "block" button next to the device. This removes it from your network when ready. Then change your Wi-Fi password to prevent it from reconnecting.

Frequently Asked Questions

Is my IP address the same as my MAC address?

No. Your IP address is a number your router assigns to identify your device on the network — it can change. Your MAC address is a permanent identifier built into your device's network hardware. Your router uses the MAC address to assign the IP address. Both appear in your router's device list, but they serve different purposes.

Can someone find my home address from my IP address?

A website or online service can see your public IP address and use it to estimate your general location — usually your city or neighborhood, not your street address. Your internet provider knows the exact address associated with your account, but they don't share that with websites. A VPN hides your real public IP from websites, replacing it with the VPN provider's IP instead.

Why does my IP address keep changing?

Your internet provider assigns IP addresses in blocks and recycles them when devices disconnect. Your local IP address (on your home network) changes if your router restarts or if DHCP reassigns it — you can prevent this by setting a static DHCP assignment in your router. Your public IP address changes less often but will shift every few months or when you restart your modem.

What should I do if I find an unknown device on my network?

Disconnect it when ready from your router's admin page, then change your Wi-Fi password to a strong one you haven't used before. Check that your router's security settings are set to WPA3 or WPA2 encryption (not WEP, which is outdated). If unknown devices keep appearing, your password may be weak or your router may have a security vulnerability — check the manufacturer's website for firmware updates.