I created the ultimate Wi-Fi password key with the most unexpected gadget - how it works

Source: ZDNet

What you’ll need

• NFC tags – they come in many shapes and sizes, from stickers to keychain disks to plastic cards. I use NTAG215‑compatible tags because they are widely available, cheap, have enough on‑board memory for my needs (504 bytes), and offer a data‑retention lifespan of at least 10 years or 100 000 write cycles.

  • Example stickers: https://www.amazon.com/dp/B075CFXY8V
  • Example keychain disks: https://www.amazon.com/dp/B077W8SN1Q
  • Example plastic cards: https://www.amazon.com/dp/B0DCK2PX35
  • Cheaper NTAG213 tags (137 bytes) are also available but may be too small for longer URLs.

• NFC reader/writer app – I use NFC Tools, available on both iOS and Android.

How to create an NFC tag

If you only need a few dozen tags, the smartphone app is sufficient. For larger batches, consider an industrial solution such as the Sato CT4‑LX.

To write a tag that opens a webpage:

1. Open NFC Tools and tap Write.
2. Tap Add a record, choose URL/URI, enter the web address, and tap OK.
3. Tap Write again and place the tag against the back of your phone. The app will detect the tag and write the data.

Securing the tag

NFC tags are rewritable, so you may want to protect them from unauthorized changes. In NFC Tools you have two options:

• Lock the tag – permanent, no password needed (quick for disposable stickers).
• Password‑protect the tag – allows future rewrites while preventing tampering (useful for reusable tags or cards).

Choose the method that fits your use case and apply it before deploying the tags.

How to test your NFC tag

1. Exit the NFC Tools app.
2. Bring the tag up to the back of your smartphone.
3. The phone should detect the tag and prompt you to open the associated web page.

Pro tip: Share your Wi‑Fi password with an NFC tag

You can store Wi‑Fi credentials on an NFC tag for easy guest access:

1. In NFC Tools, add a Wi‑Fi Network record.
2. Enter your SSID, password, and security type.
3. Write the tag as described above.

Scanning the tag with a phone will automatically connect the device to your network—perfect for sharing a guest Wi‑Fi password without typing anything.