Android
Connect to Wi-Fi Using a QR Code auf Android
Public Wi-Fi passwords are often long, case-sensitive strings that are easy to mistype on a phone keyboard. Instead of printing that string on a card, many routers, hotspots and travel SIM devices now generate a QR code that encodes the network name and password together.
Android has a built-in scanner for this inside the Wi-Fi settings, so you never leave the settings app or install a separate scanner app.
Where to find the QR scanner
Open Tap on Settings ➔ Tap on Network & internet ➔ Tap on Internet ➔ Tap on Add network ➔ Tap on Add QR code. Android switches to a live camera view, and you only need to point it at the printed or displayed QR code.
Once the camera recognizes the pattern, Android reads the embedded network name and password and connects automatically. No field stays empty, and no character needs to be entered by hand.
When this does not work
If the router only shows a plain password without a QR code, use the normal manual Wi-Fi entry instead. Some very old Android versions do not include the QR scanner option inside Add network; in that case, a third-party QR reader app combined with manually copying the decoded password is the fallback.