What’s inside a Wi-Fi QR code
A Wi-Fi QR code holds one short line of text in a format phones have recognised for years: WIFI:T:WPA;S:YourNetwork;P:YourPassword;; — the security type, the network name, and the password. The phone’s camera reads it and offers to join. There’s no link, no website and no server in between, which is why the code works offline and keeps working forever.
Semicolons, commas, colons, quotes and backslashes have special meaning in that format, so a password containing them has to be escaped or the phone reads the wrong password. The generator above escapes them for you — a common reason codes made by hand, or by careless tools, fail with “unable to join network”.
Does it work on iPhone and Android?
Yes. The iPhone camera has joined Wi-Fi from QR codes since iOS 11, and Android phones from Android 10 onward can do it from the camera, Google Lens, or the Wi-Fi settings screen. Older Android phones may need a QR scanner app. Some Android phones struggle with WPA3-only networks; if yours is one, switch the router to WPA2/WPA3 mixed mode or test before printing.
Changing your password means a new code
Because the password is written into the pattern, a Wi-Fi code can’t be edited — and a dynamic code can’t help here, since a phone only joins Wi-Fi from a code that contains the credentials themselves. If you rotate your guest password often, keep a stable guest network for the code, or plan to print a new one; making it again is free and takes seconds.
Treat the code like a password written on a card. Anyone who photographs it can join, so put it on a guest network kept separate from the devices you run your business on.