How Wi-Fi QR codes work
The code holds your network name, security type and password in a standard format that phone cameras understand. Scanning it offers to join the network straight away.
Keep it safe
Anyone who scans the code can join your network, so treat a printed copy like the password itself. A guest network for visitors keeps them off the network your own devices use. Zen Passwords keeps Wi-Fi networks in your vault and can show this kind of QR code from the item whenever a guest asks.