Is your internet acting weird lately? Websites taking forever to load, videos buffering when they never did before, or your monthly data usage suddenly through the roof? These might not just be random glitches—someone could be freeloading off your Wi-Fi! Having unwanted guests on your network isn’t just annoying because they slow down your connection. It’s also a security risk since they could potentially access your personal files or do shady stuff using your internet connection.
Signs someone might be using your Wi-Fi
Before you turn into a digital detective, it helps to know the warning signs that someone might be piggybacking on your connection. The most obvious clue is when your internet suddenly becomes slower than usual, especially during times when you’re not doing anything bandwidth-intensive. If websites that normally load quickly are crawling, or if your Netflix keeps buffering when it never did before, that could mean someone else is hogging your bandwidth. These slowdowns are particularly suspicious if they happen at consistent times, like every evening after your neighbor gets home from work.
Another red flag is unexpected spikes in your data usage. If your internet service provider has a data cap and you’re suddenly hitting it when your online habits haven’t changed, someone else might be eating through your data allowance. You might also notice strange behavior from your router, like activity lights blinking frantically when no one in your home is actively using the internet, or difficulty connecting your own devices because the network seems crowded. Sometimes your router might even restart randomly because it’s overwhelmed by the number of connected devices.
Check your router’s admin page for unknown devices
The easiest way to see who’s connected to your Wi-Fi is through your router’s admin page. Every router has a web interface that shows you exactly which devices are currently using your network. To access it, you’ll need to type your router’s IP address into your web browser. If you’ve never logged into your router before, you’ll need the admin username and password—which is often “admin” for both unless you’ve changed it (and you really should change it).
Once you’re logged in, look for a section labeled “Connected Devices,” “Client List,” or “DHCP Clients.” This will show you all the devices currently using your network, usually with their names and MAC addresses (a unique identifier for each device). Make a list of all your legitimate devices—your phones, laptops, smart TVs, gaming consoles, and smart home gadgets. Anything on the list that you don’t recognize could be a freeloader. Keep in mind that some devices might have weird names like “Android-5789” or just their model numbers, so you might need to temporarily disconnect your known devices one by one to figure out which is which on the list.
Use network scanner apps to find intruders
If checking your router’s admin page seems too technical, there are plenty of user-friendly apps that can scan your network and show you all connected devices. These apps are much easier to use and often provide more details about the devices on your network. For smartphones, apps like Fing are extremely popular. Fing shows you every device connected to your network, complete with device names, IP addresses, and even the manufacturer in many cases. This makes it much easier to identify unknown devices, as you’ll be able to see if that mystery connection is a Samsung phone or an Apple laptop.
For computers, programs like Advanced IP Scanner or Angry IP Scanner work similarly to the mobile apps, showing you everything connected to your network. These programs are free and take just a minute to download and install. The best part about using these scanner apps is that they’re designed for regular people, not IT experts. They show the information in a simple list that’s easy to understand, and some even let you give friendly names to your devices so you can keep track of them in the future. Most of these apps also let you scan your network regularly, so you can quickly check for new unknown devices whenever you suspect someone might be stealing your Wi-Fi.
Use the command prompt to find connected devices
If you don’t want to download any apps, you can use built-in tools on your computer to see who’s connected to your network. On Windows, you can use the Command Prompt to get this information. First, open the Command Prompt by typing “cmd” in the search bar and clicking on the Command Prompt app. Then, type “arp -a” (without the quotes) and press Enter. This command shows you the IP addresses and MAC addresses of all devices on your network. The downside is that this method doesn’t show you friendly device names, so you’ll just see a list of numbers that might not mean much to you unless you know the MAC addresses of all your devices.
On a Mac, you can do something similar by opening the Terminal app (find it in Applications > Utilities) and typing “arp -a” just like on Windows. Again, this will show you a list of IP addresses and MAC addresses. To make this information more useful, you can try pinging an unknown IP address to get more details. In Command Prompt or Terminal, type “ping [IP address]” (replace [IP address] with the actual address you want to check), and then try “nbtstat -A [IP address]” on Windows or “arp -a | grep [IP address]” on Mac. These commands might give you additional information about the mystery device, like its hostname, which could help identify it.
What to do if you find an intruder
So you’ve spotted a device on your network that isn’t yours—what now? The first step is to kick them off and keep them out. The quickest way to do this is to change your Wi-Fi password immediately. Log into your router’s admin page (using the method described earlier), find the wireless settings section, and create a new, strong password. Make sure you’re using WPA2 or WPA3 encryption—these are the most secure options. After changing the password, all devices will be disconnected from your network, and only those with the new password can reconnect. Write down the new password and reconnect all your legitimate devices one by one.
For even better security, consider enabling MAC address filtering on your router. This feature lets you create a whitelist of devices that are allowed to connect to your network based on their unique MAC addresses. Any device not on the list will be blocked, even if they have the correct password. While determined hackers can “spoof” MAC addresses, this measure will stop most casual Wi-Fi thieves. Also, take this opportunity to update your router’s firmware and change the admin password (not the same as your Wi-Fi password) to something strong and unique. These steps will make your network much more secure against future intrusions.
Setting up guest networks for better security
When friends or family visit and ask for your Wi-Fi password, it might seem harmless to share it. But the more people who know your main network password, the higher the risk of it being shared with others. That’s where guest networks come in handy. Most modern routers allow you to set up a separate guest network with its own password. This creates a second Wi-Fi network that gives visitors internet access but keeps them isolated from your main network. This means they can’t access your shared files, printers, or other devices on your primary network.
Setting up a guest network is simple. Log into your router’s admin page and look for “Guest Network” settings. Create a name for your guest network (like “YourName-Guest”) and set a password that’s different from your main network password. Some routers even let you set time limits on guest networks or limit the bandwidth guests can use. This is perfect if you have teenagers with friends who visit often, or if you frequently have visitors. You can freely share your guest network password without worrying about permanently giving access to your main network. And if needed, you can easily change just the guest password without affecting all your own devices.
Disable WPS for extra security
Many routers come with a feature called Wi-Fi Protected Setup (WPS) that’s designed to make connecting new devices easier. Typically, you can press a button on your router or enter a simple PIN code to connect a new device without typing the full Wi-Fi password. While this is convenient, it’s also a significant security weakness. Hackers can exploit WPS to break into your network, even if you have a strong password. The WPS PIN is only 8 digits long, which makes it much easier to crack through brute force methods than a strong Wi-Fi password. Some older routers also have vulnerabilities in their WPS implementation that can be exploited.
To protect your network, it’s best to disable WPS entirely. Log into your router’s admin page and look for WPS settings, usually under the wireless security section. Turn off all WPS options, including the push-button method and PIN method. If your router doesn’t allow you to completely disable WPS (some don’t), consider upgrading to a router with better security features. Modern security-focused routers give you more control over these features. While disabling WPS means you’ll need to enter the full Wi-Fi password when connecting new devices, the extra security is worth the minor inconvenience, especially if you’ve discovered unauthorized users on your network in the past.
Set up alerts for new device connections
Instead of manually checking for intruders every day, you can set up your network to alert you whenever a new device connects. Some modern routers have this feature built-in—check your router’s settings for notification options. If your router doesn’t offer this, you can use third-party apps and services to monitor your network. Apps like FING offer premium features that send push notifications when unknown devices join your network. This gives you immediate awareness of any potential intrusions, allowing you to take action right away before the intruder has time to do anything harmful on your network.
For more advanced monitoring, network security tools like Bitdefender Box or Firewalla can act as guardians for your entire home network. These devices sit between your router and your internet connection, monitoring all traffic and alerting you to suspicious activity. They can detect not just new devices, but also unusual traffic patterns that might indicate someone is using your network for inappropriate activities. While these dedicated security devices cost extra, they provide peace of mind and often include additional features like parental controls, ad blocking, and protection against malware. For homes with lots of smart devices or sensitive information, this extra layer of security can be well worth the investment.
Keep your router updated for better protection
Your router is the gateway to your entire home network, so keeping it updated is one of the most important steps in protecting your Wi-Fi. Router manufacturers regularly release firmware updates that patch security vulnerabilities and add new features. Unfortunately, unlike your phone or computer, most routers don’t automatically update themselves—you need to check and install updates manually. Log into your router’s admin interface regularly (aim for once a month) and look for a firmware update section. If an update is available, follow the instructions to install it. The process usually takes just a few minutes, though your internet will be unavailable during the update.
If your router is more than 5 years old, consider replacing it entirely. Older routers often have outdated security protocols and may no longer receive important security updates from the manufacturer. Newer Wi-Fi 6 routers not only offer better security features like WPA3 encryption but also provide faster speeds and better handling of multiple devices. When shopping for a new router, look for models that offer automatic firmware updates, which eliminate the need to manually check for updates. Some newer mesh Wi-Fi systems are particularly good at this, updating themselves in the background without requiring any action from you.
Keeping your Wi-Fi secure doesn’t have to be complicated. By regularly checking for unknown devices, changing your passwords, setting up a guest network, and keeping your router updated, you can prevent most Wi-Fi theft. Remember that your home network contains a lot of personal information, from the websites you visit to the smart devices you use, so it’s worth taking the time to secure it properly. Start with the simple check for unknown devices today, and you might be surprised by what—or who—you find!
