What happens when someone scans it
The code holds your network name, the password and the security type in a format phones recognise. When a guest points their camera at it, the phone offers to join the network. They tap once and they are connected. Nothing is typed, and nobody has to read your password out loud across a room.
The details are stored in the printed pattern, not on a server, so the code keeps working for as long as your network keeps the same name and password.
Fill in the fields carefully
Open the WiFi QR code generator. There are three things to get right.
- Network name (SSID). Type it exactly as it appears on your phone's WiFi list, including capital letters, spaces and punctuation. "Cafe_Guest" and "cafe_guest" are different networks to a router.
- Password. The same rule applies. A single wrong character produces a code that looks fine and fails silently. Use the eye button in the generator to check what you typed before you download.
- Security type. Choose WPA2 unless you know otherwise. It covers almost every router made in the last fifteen years. Pick "None" only for an open network with no password.
The generator never sends any of this anywhere. The password stays in your browser and goes straight into the code.
The WPA3 catch
Newer routers offer WPA3. Most of them run it in a mixed mode that also accepts WPA2, and for those the WPA2 option in the generator is the right choice. Only pick "WPA3 only" if your router is set to WPA3 with WPA2 switched off. If you choose WPA3 for a mixed network, some phones will refuse to join.
If you are not sure how your router is set, choose WPA2 and test with two different phones.
Printing it for guests
A WiFi code is usually scanned from close range, so it does not need to be large. A code about 3 cm wide works for a table card or a sticker by the till. For a sign on a wall that people scan from a metre away, make it 10 cm or more. The print size guide has the full rule.
Add a frame with the text "Scan to join WiFi" so people know what the code does before they point a camera at it. Keep the code on a white or very light background, and leave the empty margin around it untouched.
Print one copy, scan it with an iPhone and an Android phone, and confirm both actually connect before you print the batch.
When the code scans but does not connect
- The network name or password has a typo. Compare the code's contents against the router, character by character. The generator can show you the exact data inside the code.
- The security type is wrong. Try WPA2 if you chose WPA3, or the other way round.
- The phone is old. Some older phones read the code but only show the details as text. The guest can still copy the password from there.
- The network is hidden. Phones can join a hidden network from a code, but a few need the name entered manually first.
Who can read the password
Anyone who scans the code, and anyone who photographs it, can read the password. That is the same as writing it on a board, so treat the code the same way. Put guest codes on a separate guest network rather than the one your own devices and tills use. If you change the password, the old code stops working and you print a new one.