What to KnowDisconnect all of your devices from Wi-Fi, then look at the router to see if any lights are flickering (indicating that something's connected).Try a third-party networking scanning app. We like Fing, which is available for Android and iOS.If you're comfortable doing so, check your admin logs to verify which devices have recently connected to your network.
This article outlines three ways to check if someone is using your Wi-Fi network without your permission by unplugging your devices, using the Fing network scanner app, and looking at the router's admin logs.Take Back Your Wi-Fi: How to Block Users and Protect Your Network
Unplug Everything and Look at Your Router
If you're fairly inexperienced with routers and home networks and you're left thinking 'how can I tell if someone is using my Wi-Fi', there's a very quick and simple way to check—disconnect your devices. Here's what to do.
This method works best when you only have a few smart devices in your home like a laptop or two or only a couple of smartphones. If you have multiple devices connected to your network, it might get complicated unplugging them all.
Go into each room of your house and unplug any devices that connect to your Wi-Fi.
Switch off Wi-Fi on any portable devices like your smartphones, tablets, and laptops.
Go to your router and look to see if any lights continue to flicker on the router.
If the router continues to look 'busy' and the lights are flashing, it's very likely that someone else (or some device) is using your Wi-Fi. Make sure you've really disconnected every one of your devices.
Use an App to Trace Who's Using Your WI-Fi
There are several apps out there that make it very simple for you to scan your network and see if anyone is accessing it that you don't recognize. Many of these apps are free and take seconds to use. One of our favorites is Fing which is available for both Android and iOS devices. Here's how to use it to trace who's using your Wi-Fi.
Other free Wi-Fi analyzer apps are also available and useful.
Download Fing from the App Store or Google Play Store.
Tap Scan for Devices. You might be asked at this step to choose how to identify devices: MAC address or IP address. Either one is fine to pick.
Your smartphone needs to be connected to your Wi-Fi network for this to work.
Wait for the app to finish scanning your Wi-Fi network.
Scroll through the list to check you recognize all the devices connected to your network.
You can click on a device name to learn more about it.
Check Your Administrator Logs
If you feel comfortable diving into your router's administration logs, you can find out more about what devices have connected to your router in recent times. Different routers have slightly different configurations and option names but the format is roughly the same although it does involve a little digging around. Here's what to do.
Log into your router's admin panel.
Find a page listing the MAC (Media Access Control) addresses connected to your computer and check that it matches up with the correct number of devices you have at home.
Router logs keep information on old devices you might not have connected any more so bear that in mind. That's often why an app works better, but admin logs can be useful for learning a bit more about the inner workings of your network.