Wi-Fi via QR code: is it safe
A QR code is no less secure than a password written on a board by the till. But without a few settings guest Wi-Fi is a risk.
What the scanner sees
The password is stored in the code as plain text. Anyone who scans the sign can read it and share it. So the code itself is not protection — the network has to be protected.
Guest network settings
- Create a separate guest network in your router settings.
- Turn on client isolation so guests cannot see each other’s devices.
- Block guest access to the local network: till, cameras, printers, computers.
- Limit speed so one guest cannot take the whole connection.
- Use WPA2 or WPA3 encryption.
When to change the password
| Situation | What to do |
|---|---|
| Neighbours or strangers use the network | Change the password and reprint the code |
| An employee with router access left | Change the router admin password |
| Routine rotation | Every few months for busy venues |
The guest network password and the router admin password are different things. The code only grants internet access and must never contain the admin password.
Open network or password
An open network without a password does not encrypt traffic between phone and router. A password network shared via QR code is just as convenient for guests, but its traffic is encrypted — so a code with a password beats an open network.
FAQ
Can someone read the password from the QR code?
Yes, scanners show the password. That is exactly why the guest network must be separate from your work network.
Do I need to reprint the code after changing the password?
Yes, the password is written into the pattern. Sign holders with replaceable inserts make this easy.