Wi-Fi QR codes for cafés, offices and short-term rentals

Reading a 24-character password aloud across a counter is a small, repeated friction that a Wi-Fi QR code removes entirely. The guest points a camera at a card, taps a prompt, and they are online.

What is actually in the code

There is no server and no app. The code carries a short text string in a format both Android and iOS recognise:

WIFI:T:WPA;S:Cafe-Guest;P:your-password;H:false;;

T is the security type, S the network name, P the password, and H marks a hidden network. The separators matter: an SSID or password containing a semicolon, comma, colon, quote or backslash has to be escaped with a backslash, or the scanning device reads the fields wrongly. Our generator does that escaping for you, which is worth checking if you are building the string by hand.

Device support

• iOS 11 and later: the built-in Camera app offers to join the network.
• Android 10 and later: the Camera or Google Lens joins directly. Android can also generate a code for a network the phone is already on, under network settings.
• Older Android: usually works through Google Lens or a third-party scanner.
• Laptops: no native support, but the password is still readable if someone scans with a phone and types it over.

The security part people skip

A Wi-Fi QR code is your password in a machine-readable form. Printing it and sticking it on a wall makes your password public to anyone who can photograph that wall — including through a window, from the street, or in the background of a customer's social post.

That is fine, as long as the network it unlocks is one you are happy to be public. It is not fine if the same network reaches your point-of-sale terminal, your NAS or your office printers.

1. Put guests on a separate guest network or a dedicated VLAN, never the network your own devices use.
2. Turn on client isolation so guests cannot see each other's devices — an open shared network is a comfortable place to run a scanner.
3. Rate-limit the guest network so one visitor cannot saturate the line.
4. Rotate the guest password periodically and reprint the card. If that sounds tedious, that is the honest cost of a printed credential.
5. Never encode the password for a network with access to payment or back-office systems.

Practical deployment

Print the code at 3–4 cm for a table card, larger for a wall sign that people scan while standing. Include the network name in readable text beside it, so someone with a laptop knows which network to look for. Laminate anything that will live on a table.

For short-term rentals, put the code in the welcome book and beside the router, and keep error correction at M or higher — these cards get handled constantly and pick up scuffs.

One last note on privacy: because the encoding happens in your browser here, the password you type is never transmitted. You can verify that with the network tab open. For a credential you are about to print and hang on a wall, it is still worth knowing that generating it did not quietly copy it to a third party.