You can see who is connected to your Wi-Fi in the router's admin page under Connected Devices (sometimes Clients, DHCP, or Network Map), in the router manufacturer's phone app, or with a network scanner app on your phone. The list shows each device's name, its address on the network, and its MAC address. An unfamiliar device is not always a neighbor: more often it is a forgotten gadget, an old phone, or the TV. But if there really is a stranger, changing the password and closing the hole takes ten minutes.

Method 1: the router's admin page

  1. In a browser, open the router's address: usually 192.168.0.1 or 192.168.1.1 (printed on the sticker underneath).
  2. Sign in with the admin password. If it is still the factory default, change it now; that is a separate hole.
  3. Find Connected Devices, Clients, DHCP Client List, or Network Map.
  4. You get a list: hostname, IP, MAC, sometimes device type and connection time.

Method 2: the manufacturer's app

TP-Link Tether, ASUS Router, Netgear Nighthawk, Google Home for Nest Wi-Fi, eero, Xiaomi Home: most have an app with the client list on the first screen and a one-tap block button.

Method 3: a scanner on your phone

Apps such as Fing show every device on the network with the manufacturer inferred from the MAC address. Handy if the admin page is hard to reach, but a scanner only sees devices that answer at the moment of the scan.

How to tell a stranger

Go through the list and match it against what you own: phones, laptops, TV, console, speakers, vacuum, bulbs, cameras, printer, watch, e-reader. The manufacturer from the MAC helps: Apple, Samsung, Amazon, TP-Link. Signs of a stranger: an unfamiliar manufacturer, a device that appears at particular hours, a name like "android-..." when nobody at home has an Android phone.

One caveat: modern phones use a random MAC address for each network, so the same device of yours may appear under different addresses. Do not panic at duplicate Apple or Samsung entries.

Why a stranger on your network matters

  • They use your bandwidth and, on some plans, your data.
  • They can see the devices on your network and try passwords on the printer, NAS or camera.
  • Everything they do online comes from your IP address; to your ISP and to websites, it is you. What an address reveals is in what can someone do with my IP address.
  • If the admin password is the factory default, they can reconfigure the router, for example swap the DNS.

What to do

  1. Change the Wi-Fi password. Every device disconnects; the stranger cannot return without the new one. Use a long phrase from the password generator.
  2. Enable WPA3 or WPA2-AES and disable WPS: WPS is how a stranger may have gotten in without the password.
  3. Block the stranger's MAC in the admin page if the router supports it. Not a barrier to a determined attacker, but it stops casual neighbors.
  4. Change the admin password if it was the default.
  5. A guest network for guests and smart devices, with client isolation, so even someone who connects cannot see your computers.
  6. Update the firmware: router vulnerabilities are another way in.

The full router checklist is in how to secure your home Wi-Fi router.

If there are no strangers but the internet is slow

Clean list, slow network: look for a cause, not a neighbor. A crowded 2.4 GHz band, a router behind a wall, old firmware, or one of your own devices downloading updates. Many routers show per-client usage in the admin page.

What the router cannot fix

Even in a perfectly private home network, the ISP sees the site names and DNS queries of every device. Closing that requires a VPN, on each device or on the router; the breakdown is in what can my ISP see.

404 VPN has apps for phones, computers and TVs and WireGuard configurations for routers, so the whole house can be covered with one connection. Get started here.