Where to actually put the card
A laminated table tent on the cafe counter or each table works because it's at eye level right when someone's ordering. In an Airbnb, a framed card in the welcome binder covers guests who read instructions, but a second copy stuck to the fridge catches everyone else — that's the spot people check first in an unfamiliar kitchen.
In a hotel room, put it on the desk or nightstand next to the room info card, not buried in a folder. For an office, a small sign at reception with the guest network code saves your front desk from repeating the same password out loud twenty times a day.
A quick word on security
If your router supports a separate guest network, use that one for the printed code rather than your main admin Wi-Fi — it's a small setup step that keeps visitors off the same network as your other devices. This isn't about fear-mongering, it's just good practice for anything printed and left where strangers can see it.
It also means you can hand out the guest password freely without touching whatever secures your own equipment. Most routers make a guest network a five-minute setup, and it pairs naturally with a code meant for public display.
No destination to worry about changing
A website QR code has a real concern: if the destination page moves or gets taken down later, the code stops working. A Wi-Fi code doesn't have that problem in the same way — there's no external destination at all, just the network credentials baked directly into the pattern.
So if you ever change your Wi-Fi password, there's nothing to fix online, no dashboard to update — you just generate a new code with the new password and print a fresh card. The old one simply stops connecting, and that's the whole story.