How do you write Wi-Fi credentials to a tag?
Choose the Wi-Fi record type in a writing tool, enter the network name, the security type and the password, and write. On Android tapping the tag offers to join the network. On iPhone the same record does not produce that result, so any deployment needs a fallback.
Writing the record
A tool offering a Wi-Fi option handles the encoding for you. You supply the network name exactly as it is broadcast, the security type, and the password.
Exactly as broadcast matters more than it sounds. The network name is case sensitive and a trailing space is invisible and fatal. Copying it from the phone's own network list is safer than typing it.
The fields that matter
| Field | What to enter | Common mistake |
|---|---|---|
| Network name | The name as broadcast, case sensitive | Retyping it with a wrong capital or a trailing space |
| Security type | The mode the router actually uses | Choosing a mode the router does not run |
| Password | The network key | Special characters mistyped, or an old password |
| Hidden network | Set if the name is not broadcast | Leaving it unset on a hidden network |
A Wi-Fi record is longer than a URL, so it will not fit on the smallest tags. Read the free space before writing rather than discovering the limit on the tenth tag.
What happens on Android
Tapping the tag brings up a prompt to join the network, and accepting it connects without anyone reading a password aloud. For a guest network at home, a holiday rental or a small office, this is genuinely good.
It also updates cleanly. Change the password, rewrite the tag, and every future guest gets the new one without anything else changing.
Planning for everyone else
An iPhone will not join a network from this record, and no version of writing it differently changes that. Anyone deploying a Wi-Fi tag for mixed visitors needs an answer for half of them.
The workable answers are a printed QR code beside the tag, since both platforms join networks from a scanned code, or a printed password as a plain fallback. Both are unglamorous and both work.
What does not work is assuming visitors will figure it out. A tag that does nothing on an iPhone reads as a broken tag, which is worse than no tag at all.
Think before putting your main network on a tag
Anyone who can touch the tag gets the password, including people you would not have told. A guest network with no access to your other devices is the right place for this, and most routers offer one.
Frequently asked questions
Why does my Wi-Fi tag do nothing on an iPhone?
The record type is not acted on by iOS. It is a platform limitation rather than a fault in the tag, and the practical answer is a QR code or a printed password alongside.
Can I write a Wi-Fi tag for a hidden network?
Yes, and the hidden flag has to be set, otherwise the phone will look for a network it cannot see. The network name must also be exact, since there is no list to correct it against.
Is putting my Wi-Fi password on a tag a security risk?
It is a deliberate trade. Anyone with physical access to the tag obtains the password, which is why a guest network isolated from your other devices is the right thing to share this way.
Does the tag need updating when I change the password?
Yes, and that is a one minute rewrite on an unlocked tag. It is also the reason not to lock a Wi-Fi tag, since passwords change more often than people expect.