You can check if someone is using your WiFi by logging into your router’s admin panel and reviewing the list of connected devices. Navigate to the DHCP client list or attached devices section, compare each entry against your known devices, and investigate any unrecognised MAC addresses or hostnames that appear on the network.
Why Unauthorised WiFi Access Is a Serious Risk
An unknown device on your network is not just stealing bandwidth. It can intercept unencrypted traffic, launch man-in-the-middle attacks against your devices, access shared files and printers, and use your IP address for illegal activity that traces back to you. According to the 2025 Norton Cyber Safety Insights Report, 31% of UK households had at least one unauthorised device connected to their home WiFi at some point during the year.
If your connection feels slower than usual, your router shows higher data usage than expected, or you see unfamiliar devices in your network list, someone may be piggybacking on your WiFi. Our guide on testing whether your WiFi is actually secure covers the full diagnostic process.
How to Check Connected Devices on Your Router
Step 1: Access Your Router Admin Panel
Open a browser and type your router’s IP address, typically 192.168.0.1 or 192.168.1.1. Log in with your admin credentials. If you have never changed them, check the sticker on the bottom of your router for the default username and password. Change these defaults immediately after logging in.
Step 2: Find the Connected Devices List
Look for a section labelled “Connected Devices,” “DHCP Client List,” “Attached Devices,” or “Client List.” The exact wording varies by manufacturer. This list shows every device currently connected to your network, along with its IP address, MAC address, and sometimes its hostname.
Step 3: Identify Each Device
Cross-reference every entry against your known devices. Phones, laptops, tablets, smart TVs, game consoles, and IoT devices all appear here. If you see a device you cannot identify, note its MAC address and check the manufacturer prefix using an online MAC address lookup tool. This narrows down the device type.
Router Detection Methods Compared
| Detection Method | Difficulty | Accuracy | Shows History | Real-Time Alerts | Best For |
|---|---|---|---|---|---|
| Router admin panel | Easy | High | No | Some routers | Quick manual checks |
| Fing (mobile app) | Easy | High | Yes (premium) | Yes (premium) | Regular monitoring |
| Wireless Network Watcher (Windows) | Easy | High | No | Yes | Windows desktop scanning |
| Angry IP Scanner | Moderate | High | No | No | Advanced users and IT pros |
| Router logs (syslog) | Advanced | Very high | Yes | Configurable | Forensic analysis |
| Wireshark packet capture | Advanced | Very high | Yes | No | Deep traffic inspection |
How to Block Unauthorised Devices
Change Your WiFi Password Immediately
The fastest way to remove all unauthorised users is to change your WiFi password. Use WPA3 if your router supports it, or WPA2-AES at minimum. Choose a password with at least 16 characters mixing upper and lowercase letters, numbers, and symbols. Every legitimate device will need to reconnect with the new password, which also forces off any intruder.
Enable MAC Address Filtering
MAC filtering lets you create a whitelist of approved device MAC addresses. Any device not on the list gets rejected. While MAC addresses can be spoofed by a determined attacker, this adds a layer that stops casual freeloaders. Our detailed walkthrough on blocking devices at the router level covers MAC filtering configuration for all major router brands.
Disable WPS and Strengthen Router Settings
WiFi Protected Setup (WPS) contains a known vulnerability that allows brute-force PIN attacks in hours. Disable it in your router settings. Also disable remote management, enable your router’s built-in firewall, and update the firmware to the latest version. For a complete hardening process, follow our step-by-step guide to securing your home WiFi.
Signs Someone Is Stealing Your WiFi
Watch for these indicators: your internet speed drops significantly during off-peak hours, your router’s activity lights blink rapidly when no one in your household is online, your monthly data usage spikes without explanation, you find unknown devices in your router’s client list, or you receive ISP warnings about unusual traffic patterns. Any two of these occurring together warrants an immediate investigation.
Frequently Asked Questions
Can your neighbour connect to your WiFi without the password?
Yes, if your router uses WEP encryption (which can be cracked in minutes), has WPS enabled (vulnerable to brute-force attacks), or still uses the default password printed on the router. Switching to WPA3 or WPA2-AES with a strong custom password and disabling WPS eliminates these attack vectors entirely.
Does checking connected devices show all WiFi users?
The router’s DHCP client list shows devices that received an IP address automatically. A technically skilled intruder using a static IP assignment could avoid this list. To catch all devices, use an ARP scan tool like Fing or Wireless Network Watcher, which detect every device communicating on the local network regardless of how it obtained its IP address.
How often should you audit your WiFi network for unknown devices?
Check your connected devices list at least once per week. Set up push notifications through your router’s app or a third-party tool like Fing to receive alerts whenever a new device joins the network. Monthly password rotations are excessive for most households, but changing your WiFi password every six months and after any guest access is a practical schedule.