A Wi-Fi QR code holds the network name, the security type and the password in a format both iPhone (iOS 11 and later) and Android (10 and later) recognise straight from the camera app. The phone shows "Join network" and connects. Nothing is downloaded, nothing is installed.
Because the password is inside the code, it matters where the code is generated. Here it is built on your own device: type the password, the code appears, and no copy of it goes anywhere. That is a real difference from generators that run on a server and keep logs.
Print it where people sit: table tents, the back of a menu, the fridge in an Airbnb, a frame by the till. Codes read from a table need to be about 3 cm wide; use the PDF export to get exactly that. If your network is hidden, switch the Hidden option on so the phone knows to look for it.
Questions
Does a Wi-Fi QR code work on iPhone?
Yes. Since iOS 11 the built-in Camera app recognises Wi-Fi codes and offers to join the network. No extra app is needed. On Android 10 and later it works the same way from the camera or Google Lens.
Is my Wi-Fi password sent to your server?
No. The code is generated in your browser. You can switch off your internet connection after the page loads and it still works.
What if I change the Wi-Fi password?
A static code cannot be edited, so you print a new one. It takes a minute and costs nothing. For a code you want to re-point without reprinting, see lifetime editable codes.
Which security type should I pick?
Almost every router made since 2010 uses WPA2 or WPA3, and both are covered by the WPA option. Only choose WEP for very old equipment, and nopass for an open network with no password.