NTAG 213 / 215 / 216

NTAG 213 holds ~144 bytes of user memory — enough for a URL plus a few parameters. It is the cheapest NFC chip in volume and is the right choice when the tag just needs to open a SmartLink.

NTAG 215 (~504 bytes) and NTAG 216 (~888 bytes) are physically larger and store more data on-chip — useful when the experience must work offline, or when a longer signed URL, vCard or NDEF payload needs to live on the tag itself.

All three are read-write, lockable, and supported by every NFC-capable phone. None of them are cryptographic — for tap-unique authentication you want NTAG 424 DNA instead.