New Features of NTAG21x NFC Tags

Announced in October 2012, NTAG21x are the second generation of NFC Integrated Circuits made by NXP and have interesting features.

The NTAG21x Series includes NTAG210, NTAG212, NTAG213, NTAG215 and NTAG216. The last digit indicates the usable memory of the chip (the higher the number, the bigger the memory), in addition to some minor features.

Originality Signature

This is definitely one of the most interesting features, because discourages any attempts to fake NXP chip passing off as real ones, and providing security about the authenticity of the integrated circuits. That means also the warranty of the unique UID of each NFC chip built.

With the unique IDs, this feature is essential for the development of services of authenticity through NFC technology.

Password Protection

This function allows you to lock the encoding of a NFC Tag with a password. This means that those who'll find a password-protected NFC Tag will be able to read it, but not to edit or delete the stored data.

It is a function rather useful, especially for Tags that must be positioned in public places. Not to be confused with cryptography, which instead allows you to read the contents of a Tag only if you are in possession of the encription key.

Scan Counter

This feature allows you to store the number of times a Tag has been scanned. The number can be dynamically "pasted" into the URL or other content of Tag when you're encoding it. To use this feature, we recommend to use the Android app developed by NXP: NFC TagWriter by NXP.

This feature is not present in NTAG210 and NTAG212 ICs.

UID Ascii Mirroring

The UID Ascii Mirroring allows you to "paste" the NFC Tag UID into an URL, like '', where the 7 byte UID is put in place of 'xxxxxxx'. To use this feature, we recommend the Android app developed by NXP: NFC TagWriter by NXP.

Faster Speed and Wider Reading Range

Being new generation ICs, NFC Tag of the NTAG21x series were improved even in their basic features: the speed of reading/writing and the operativity range. The improvement of these two parameters, it must be said, is rather small: it is about 10% more than the previous chip.

Anyway, the range is still connected to the size of the antenna and the power of the NFC reader/writer. In any case this represents an improvement respect to previous chips.