You paste your Wi-Fi password into a free "QR generator" website. That site now knows your network name and password. Read that sentence again.

Most people hand their Wi-Fi to guests by shouting a 20-character string across the room three times. There's a better way that keeps your secrets on your own machine.

Here are 4 steps to self-host a Wi-Fi card guests scan and forget.

1. Skip the online generators — they see everything

Type "wifi qr code" into Google and you'll find a hundred sites happy to make one for free. The catch: you typed your real password into a stranger's server. Even if they promise not to store it, you have no way to check.

Generate the code on hardware you control instead. No password ever leaves your house.

2. Run a tiny generator locally

The format is simple. Wi-Fi QR codes are just plain text like this:

WIFI:T:WPA;S:YourNetworkName;P:YourPassword;;

Any phone camera reads that and offers to join. Install the qrcode Python tool on your home server or laptop:

pip install qrcode
qr "WIFI:T:WPA;S:MyHouse;P:supersecret123;;" > wifi.png

That's it. One file, one command, zero cloud. Print wifi.png and stick it on the fridge.

3. Make a guest network first — then card that

Don't put your main password on a card at all. Most routers let you create a separate guest network in two clicks. Guests get internet; they never touch your printers, cameras, or file server.

Generate the QR code for the guest network only. Now if the card gets photographed at a party, the worst case is someone joins your throwaway network — not your whole home.

4. Host it as a little web page for yourself

If you already run something like a home dashboard or a self-hosted notes app, drop the QR image on a page there. Bookmark it. When a guest arrives, open the page on your phone and hold it up. They scan your screen. Done in three seconds, no printing.

Want it fancier? Self-hosted apps like Homepage or a simple static site served by Caddy can hold the card behind your own login. Rotate the guest password monthly and regenerate the code — a 30-second habit that keeps old guests locked out.

The takeaway

Run this one command today on a machine you own:

pip install qrcode && qr "WIFI:T:WPA;S:GUEST_NAME;P:GUEST_PASS;;" > wifi.png

Replace the guest network details, print the image, and never read your password aloud again — or leak it to a website that had no business seeing it.