How to Write Wi-Fi to an NFC Tag (So Guests Join in One Tap)

To share Wi-Fi with a tap, write your network name (SSID), password and security type to an NFC tag as a Wi-Fi record. When an Android phone taps the tag, it offers to join the network straight away — nobody has to read a password off a card or type it in.

iPhones are the exception: they don't join Wi-Fi networks from NFC tags on their own. The practical fix is to stick a Wi-Fi QR code next to the tag, so every guest has a one-step option.

What you need

• A blank NFC tag. NTAG213 (144 bytes) is enough for most home and guest networks; choose NTAG215 if your network name or password is very long
• Your network name exactly as it appears (it's case-sensitive), the password, and the security type
• NFC Wizard on your phone. Wi-Fi writes are a Premium tool — on the free plan you can try it once by watching a short ad

Write the tag in NFC Wizard

• Open Write Tag and choose Wi-Fi — or go to Templates and pick Guest Network Access, which remembers your details for next time
• Enter the network name and password, and pick the security type: WPA/WPA2 for almost every modern router, WEP for very old ones, or None for an open network
• Tap write and hold a blank tag flat against the back of your phone until the write confirms
• Test it: tap the tag with an Android phone that isn't already on the network. It should offer to connect

Already have a Wi-Fi QR code?

Many routers print a Wi-Fi QR code on a sticker, and lots of venues already display one. Use QR to NFC in NFC Wizard: scan the code with the camera or pick a photo of it, and the app recognises it as a Wi-Fi network and writes the same details to a tag. Keep the QR code up too — it's your iPhone fallback.

Keep the tag from being rewritten

A blank-looking sticker in a public place can be rewritten by anyone with an NFC app. Someone could swap your network for a lookalike they control. After testing, password-protect the tag (Tag Tools → Lock → Set Password): phones can still read it, but nobody can change it without your password.

Only lock a Wi-Fi tag permanently if the password will never change. When you rotate the Wi-Fi password, a password-protected tag can be unlocked and rewritten; a permanently locked one has to be thrown away.

Security trade-offs to know

• Anyone who taps the tag can read the password, so use a guest network rather than your main one
• Changing the Wi-Fi password means rewriting every tag — another reason to protect, not permanently lock
• A tag is only as private as the place it's stuck: inside a guest room is different from a shop window

Where to put it

Place the tag where people already pause: the entrance shelf, a guest-room bedside table, the café counter or each table. Label it — "Tap for Wi-Fi" with a small NFC symbol — because an unmarked sticker gets ignored. Indoors on a smooth surface, a plain sticker is fine; on metal, use an on-metal tag.