What you can actually find out about IP addresses
Finding someone's IP address on your own network is straightforward if you have the right tools. An IP address is a number that identifies a device connected to your network — like a home WiFi network or a work computer system. You can see which devices are connected and what their IP addresses are using built-in tools on Windows, Mac, or Linux, or by logging into your router.
What you cannot do is find the IP address of someone on the internet just by knowing their name or email. That information is private. If someone sends you an email or messages you online, their IP address is not visible to you. If you need to find an IP address for a device you do not own or control, you would need that person's permission or a legal reason to ask your internet provider or a service provider to share it.
This guide covers how to find IP addresses on networks you manage, how to read what your router shows you, and what the limits are on finding information about devices or people online.
Key Takeaways
- You can see the IP addresses of devices on your own network using your router's admin panel, or using command-line tools like ipconfig on Windows or ifconfig on Mac.
- Your router keeps a list of every device connected to it, including their IP addresses and the time they connected — this is the easiest place to look first.
- Finding someone's IP address from their email, social media, or online activity requires their permission or a legal process; you cannot do it yourself.
- IP addresses on your home network are usually temporary and change regularly, so a device's address today may not be the same tomorrow.
- If you suspect someone is using your network without permission, check your router's connected devices list and change your WiFi password.
Check your router's admin panel for all connected devices
Your router keeps a record of every device connected to it, including the device's IP address, its name, and when it connected. This is the fastest way to see what is on your network. To access your router, open a web browser and type your router's IP address into the address bar — usually 192.168.1.1 or 192.168.0.1. If neither works, check the sticker on the back or bottom of your router; it will show the correct address.
Log in using the username and password printed on your router. If you changed the password and do not remember it, you can reset the router by holding the reset button for 10 seconds, but this will erase your WiFi settings. Once you are logged in, look for a section called "Connected Devices," "DHCP Clients," "Device List," or "Attached Devices" — the exact name depends on your router brand. You will see a table showing each device's name, IP address, and sometimes the time it connected.
Write down the IP address next to the device you are looking for. If you do not recognize the device name, the IP address alone will not tell you much — you would need to cross-reference it with the device itself or ask the person using it.
Use Windows command tools to find a device's IP address
If you are on a Windows computer and want to find the IP address of another device on your network, you can use the Command Prompt. Press the Windows key and type cmd, then press Enter to open Command Prompt. Type ipconfig and press Enter to see your own computer's IP address and network details.
To see all devices on your network, type arp -a and press Enter. This shows a list of devices that your computer has recently communicated with, along with their IP addresses and MAC addresses (a unique identifier for each device). The list may include devices you do not recognize — these are usually printers, smart home devices, or phones on your network.
If you want to find a specific device, you can also use nslookup followed by a device name or hostname. For example, typing nslookup printer will search for a device named "printer" on your network and show its IP address if it is found.
Use Mac and Linux tools to find network devices
On a Mac, open the Terminal application (found in Applications > Utilities). Type ifconfig and press Enter to see your own computer's IP address and network information. To see other devices on your network, type arp -a and press Enter — this shows devices your Mac has recently communicated with, similar to the Windows command.
On Linux, the commands are the same: ifconfig shows your own network details, and arp -a shows other devices. Some newer Linux systems use ip addr instead of ifconfig. If you want to scan your entire network for active devices, you can use nmap, but this tool must be installed separately and requires some technical knowledge to use correctly.
Both Mac and Linux also allow you to access your router's admin panel the same way as Windows — type the router's IP address into a web browser and log in with your router's username and password.
What you cannot find out about someone online
You cannot find someone's IP address just by knowing their email address, phone number, or social media username. Email providers, social media platforms, and messaging apps do not show you the IP address of the person you are communicating with. Even if someone sends you an email, you cannot see where they are located or what device they used.
If you receive a threatening email or message and want to report it, you can forward it to the platform's support team or to law enforcement — they have the legal authority to request IP address information from service providers. You do not have that authority yourself, and attempting to find someone's IP address without permission or a legal reason is illegal in most places.
Some websites and online services do log the IP addresses of visitors, but that information is private to the website owner. If you run a website and want to see visitor IP addresses, you can check your web server logs, but you cannot see the IP addresses of visitors to other people's websites.
What to do if you find an unknown device on your network
If you check your router and see a device you do not recognize, the first step is to change your WiFi password. Go back to your router's admin panel, find the WiFi or Wireless settings section, and change the password to something strong and unique. This will disconnect all devices, and only devices with the new password can reconnect.
After you change the password, reconnect your own devices one by one. If the unknown device does not reconnect, it means someone was using your network without permission and no longer has access. If it does reconnect, it is likely a device you own but did not recognize by name — check your phones, tablets, smart home devices, and computers to see which one it is.
If you are concerned about security, you can also enable MAC filtering in your router settings, which allows only specific devices to connect. However, this requires you to manually add each device's MAC address, which is more work but more secure. Your router's manual or support page will explain how to set this up for your specific model.
Understanding IP addresses on your network
IP addresses on your home or office network are usually assigned automatically by your router using a system called DHCP. This means a device's IP address can change each time it reconnects to the network. If you see a device with IP address 192.168.1.50 today, it might have a different address tomorrow. This is normal and not a problem.
If you need a device to always have the same IP address — for example, a printer or security camera — you can assign it a static IP address through your router's settings. This is called "IP reservation" or "static DHCP" and ensures the device always gets the same address. This is useful if you want to access the device reliably by its IP address.
The numbers in an IP address follow a pattern. On most home networks, addresses start with 192.168 or 10.0. The last number (like the 50 in 192.168.1.50) is what changes between devices. Your router itself usually has the address ending in .1, like 192.168.1.1. Understanding this pattern helps you recognize which addresses belong to your network and which do not.
Frequently Asked Questions
Can I find someone's IP address from their email or text message?
No. Email providers and messaging apps do not show you the sender's IP address. Even if you open an email, the sender's location and device information remain private. Only the email or messaging service provider has access to that information, and they will only share it with law enforcement through a legal process.
What is a MAC address and how is it different from an IP address?
A MAC address is a unique identifier for a device's network card, while an IP address is the number that identifies the device on a network. MAC addresses do not change, but IP addresses can. Both appear in your router's device list. You need the MAC address if you want to set up MAC filtering or assign a static IP address to a device.
Is it illegal to find someone's IP address?
Finding the IP address of a device on your own network is legal. Finding someone's IP address without their permission or a legal reason is illegal in most places. If you need someone's IP address for a legitimate reason, ask them directly or contact the service provider with a court order.
Why does my device have a different IP address every time I connect?
Your router assigns IP addresses automatically using DHCP, and these assignments are temporary. When your device disconnects and reconnects, it may receive a different address. If you want a device to keep the same address, you can set up IP reservation in your router's settings.
What should I do if I see a device on my network I do not recognize?
Change your WiFi password immediately through your router's admin panel. This disconnects all devices. Reconnect your own devices one by one. If the unknown device does not reconnect, someone was using your network without permission. If it does reconnect, check your phones, tablets, and smart devices to identify it.