NTAG213 is an NFC chip from NXP's NTAG21x family, operating at 13.56 MHz under ISO/IEC 14443 Type A. It carries 180 bytes of total memory, of which 144 bytes are available for your own data — comfortably more than any short URL needs.
The NTAG21x family, side by side.
| NTAG213 | 180 bytes total, 144 bytes user memory |
|---|---|
| NTAG215 | 540 bytes total, 504 bytes user memory |
| NTAG216 | 924 bytes total, 888 bytes user memory |
| Operating frequency | 13.56 MHz, ISO/IEC 14443 Type A |
| Typical read range | Under 4 cm with a phone — it is a tap, not a scan |
| Write protection | One-way lock bits; locking is permanent |
A URL of 30 characters needs roughly 37 bytes once the NDEF wrapper is counted. Against 144 bytes of user memory, the larger chips buy nothing for this job.
Where this shows up.
Vendors upsell capacity that the task cannot use. If the tag's only job is to open a page, NTAG213 is the correct chip and the cheapest one, and the difference goes into buying tags that are physically better made instead.
The common mistake.
Buying tags that arrive pre-locked or pre-programmed with a vendor's own URL. Locking is one-way — once those bits are set the tag can never be rewritten, and a card that permanently points at somebody else's page is a card you have to throw away.
Sources.
Every figure above is from one of these. They are the standard, the registry or the platform’s own documentation — read them rather than take our word for it.
- NTAG213/215/216 datasheet NXP Semiconductors
- Type 2 Tag and NDEF specifications NFC Forum
- ISO/IEC 14443 Wikipedia