If your internet speed has suddenly tanked, or you’re noticing a weird light flickering on your router in the middle of the night, there’s a decent chance someone next door is piggybacking on your connection.
You might assume that a bit of lag is just the provider having a bad day (which is certainly possible), but in a terrace or a block of flats, your signal is basically a free invitation for anyone with a bit of tech-savvy and a weak conscience. We’re not talking about a major hack here; usually, it’s just a cheeky neighbour who’s managed to guess a weak password or has been using a connection you never bothered to secure.
While it might seem like a minor annoyance, having an uninvited guest on your network is a massive security risk and a total drain on the bandwidth you’re actually paying for. Finding out for sure doesn’t require a degree in computer science, but you do need to know where to look to spot the digital footprints they’ve left behind. If you want to stop paying for the flat upstairs to stream their box sets, it’s time to check the guest list on your own router.
Check your router’s app or admin page.
Your router, which is the box that creates your Wi-Fi signal, keeps a list of every device currently connected to it. Most modern routers let you see this list either through an app on your phone or by typing a specific address into your browser, usually something like 192.168.1.1 or 192.168.0.1.
Once you’re logged in, look for a section called connected devices, device list, or something similar. You’ll see a list of everything currently on your network, and if any of the names look unfamiliar, that’s worth investigating further.
Look for a device name that isn’t yours.
Every device on a network has its own unique name, and most of them label themselves automatically. Your phone might show up as something like “Sarah’s iPhone” and your laptop might say “DESKTOP-J4KL2.” If you see something in the list you don’t recognise, it could belong to a neighbour.
The trick is to go through every device in your home and account for each one. Count your phones, laptops, tablets, smart TVs, games consoles, smart speakers, and anything else that connects to the internet. If the number of devices on your router’s list is higher than the number of things you can account for, someone else is probably on there.
Turn everything off and see what’s left.
A simple and very effective trick is to turn off the Wi-Fi on every single device in your house, or switch them to aeroplane mode, and then check the connected devices list on your router again. If anything is still showing as connected after you’ve switched everything off, it doesn’t belong to you.
This method works well because it removes the guesswork of trying to match device names to your actual gadgets, and it gives you a clear picture of what’s on your network that you didn’t put there.
Use a free app to scan your network.
If logging into your router sounds complicated, there are free apps that do the hard work for you. Fing is probably the most popular and straightforward option, available on both iPhone and Android. You download it, connect your phone to your home Wi-Fi, and it scans the network and shows you every device on it in a clear, readable list.
It also tries to identify what kind of device each one is, so you might see it label something as a Samsung phone or an Amazon device, which makes it easier to work out what belongs to you and what doesn’t.
Watch your router’s lights when everything is off.
This is one of the oldest tricks in the book, and it still works. Find the light on your router that represents Wi-Fi activity, it’s usually labelled WLAN or has a small Wi-Fi symbol next to it. Switch off or disconnect every device in your home that uses the internet.
If that activity light is still flickering when everything in your house is off, data is still moving through your network, which means something you don’t know about is connected and active. It’s not a precise method, but it’s a quick first check that costs you nothing.
What to do if you find an unfamiliar device
The fastest fix is to change your Wi-Fi password. When you do this, every device currently connected gets kicked off the network instantly, including the unauthorised one. You’ll then need to reconnect all your own devices using the new password, which takes a few minutes but is absolutely worth the effort.
Choose a password that’s long and includes a mix of letters and numbers, and avoid anything obvious like your address or a word from the dictionary. Once you’ve changed it, check the connected devices list again after a day or two to make sure nothing unexpected has come back.
Make sure your security settings are strong enough.
While you’re in your router settings, it’s worth checking which type of security your network is using. You’ll usually see options like WEP, WPA, or WPA2 and WPA3. WEP is very old and easy to crack, so if that’s what you’re using, change it immediately.
WPA2 is solid and widely supported, while WPA3 is the newest and most secure option available on modern routers. If your router offers WPA3, use it. If it only goes up to WPA2, that’s still fine for most people. The key thing is to make sure you’re not sitting on WEP without realising it.
Set up a guest network for visitors.
Most modern routers let you create a separate guest network, which is a second Wi-Fi connection with its own name and password that you can give to visitors. The clever part is that devices on the guest network can access the internet but can’t see or communicate with the devices on your main network, so your laptop and phone stay protected.
It also means that if a visitor accidentally shares your Wi-Fi details or their device gets compromised, your main network stays separate and safe. If you have friends or family round regularly who connect to your Wi-Fi, setting this up is one of the most useful things you can do.
Keep your router’s software up to date.
Routers run on software just like your phone does, and manufacturers release updates to fix security weaknesses when they find them. A lot of people set their router up on the day it arrives and never think about it again, which means they could be running software with known vulnerabilities for years.
Check your router’s app or admin page for a firmware update option, and if there’s an update available, install it. Some newer routers do this automatically, but older ones usually need you to do it manually. It only takes a few minutes, and it closes off gaps that could otherwise leave your network easier to get into.
