How to write a URL to an NFC tag
Writing a link to an NFC tag takes a few seconds. The decision that matters is which link you write, because the tag will often stay on the object for years.
What you need
- An NFC tag. NTAG213, NTAG215 and NTAG216 are the common choices. They differ mainly in memory: about 144, 504 and 888 bytes. A web link fits easily on the smallest.
- A phone with NFC. Most recent Android phones and iPhones can write tags.
- An app that writes NFC tags. Several free ones are available for both platforms.
Write the tag
- Open the writing app and add a URL record.
- Paste the link.
- Choose write, then hold the tag against the back of the phone until the app confirms.
- Close the app and tap the tag to test it. The link should open in your browser.
On iPhones the NFC antenna is near the top edge. On Android phones its position varies, so try the middle and the top of the back.
Choose a link that can stay
A standard tag stores text, not a live connection. If you write a link directly to a PDF, and the PDF later moves, the tag is broken until someone rewrites it on site.
The fix is to write a permanent link that you control and change where it leads. In TagOS each tag gets a permanent link, and you update the object page behind it from your desk. The physical tag never needs rewriting.
Common problems
- The write fails. The tag may be read-only or locked. Try a new one.
- Nothing happens on tap. Check that NFC is switched on, and on Android that the screen is unlocked. Older iPhones may need an NFC reader app.
- It doesn’t read on a machine. Metal blocks standard tags. Use a tag made for metal surfaces.
- Someone could overwrite it. Unlocked tags can be rewritten by anyone nearby. Locking a tag prevents that, but it can’t be undone, so test it first.