Every time you open Wi-Fi settings or a router's admin page, these three terms keep appearing. They sound technical and similar, yet each answers a very different question.

  • SSID: what is the network called?
  • BSSID: which transmitter am I using?
  • MAC address: who is this device?

SSID: the network name

The SSID is the name that shows in the list when searching for Wi-Fi. The router owner can change it freely, and some routers broadcast more than one SSID at once, say one for the family and one for guests.

The key point: an SSID is not a unique identifier. Anyone can create a network with exactly the same name as your favourite café's Wi-Fi. That is the basis of the fake Wi-Fi attacks covered in the guide to fake Wi-Fi and evil twins.

Hiding the SSID doesn't make a network safer either, because the name is still carried in traffic when devices connect.

BSSID: the transmitter's address

One SSID can be broadcast by several transmitters. In a home with mesh, the same Wi-Fi name comes from the router in the living room and the unit upstairs. On a dual-band router, the same name even comes from two different radios inside one box 2.4 GHz and 5 GHz.

Each of those transmitters has its own address, called the BSSID. It looks just like a MAC address, six pairs of characters such as A4:2B:8C:10:3F:7E.

Its uses in troubleshooting:

  • A phone clinging to a distant transmitter. Same network name, but the BSSID shows the phone is still on the downstairs unit when you are already upstairs. See the guide to roaming between access points.
  • Seeing which band is in use. Wi-Fi analyser apps show the BSSID with its frequency, so you can see whether a device is on 2.4 or 5 GHz.
  • Spotting fake networks. A network with the same SSID but an unfamiliar BSSID in a place with only one router deserves suspicion.

MAC address: the device's address

Every network card, in phones, laptops, TVs, cameras, has a MAC address. Routers use it to recognise devices on the local network: giving the same IP address each time, listing connected devices, or blocking particular ones.

A MAC address only applies on the local network. The websites you visit cannot see it.

Random MACs on modern phones

Because a fixed MAC address could be used to track a phone from one public Wi-Fi to the next, Android and iPhone now use a different random MAC address for each network by default.

The consequences for router owners:

  • One phone can appear as a "new" device after its network is forgotten and rejoined.
  • MAC-based blocking, speed limits, or IP reservations can stop working.
  • The router's device list can show unfamiliar names that actually belong to people in the home.

For a trusted home network, the feature can be turned off per network in the phone's Wi-Fi settings, under a name like Private address or Randomised MAC. The limits of MAC filtering are covered in the guide to MAC filtering.

The SSID is the network name and anyone can copy it. The BSSID is the transmitter's address, useful for seeing which unit and band a device is on. The MAC address is the device's address on the local network, and on modern phones it is randomised per network, worth remembering before relying on it to block or limit.

Frequently asked questions

Is the SSID the same as the Wi-Fi password?

No. The SSID is only the network name shown when searching for Wi-Fi. The password is a separate thing needed to join.

Why does my phone's MAC address keep changing?

Modern phones use a random MAC address for each network so their owners can't easily be tracked from place to place. That is why MAC-based blocking or limits on a router can stop working when this feature is on.