The NTAG212 is an NFC chip designed by NXP Semiconductors, positioned between the NTAG210 and the NTAG213 within the NTAG21x family. Compliant with the ISO/IEC 14443 Type A standard and the NFC Forum Type 2 format, it offers 128 bytes of user memory. It can be read and written by virtually all NFC-enabled smartphones.
Information
| Manufacturer | NXP Semiconductors |
| Family | NTAG21x (NTAG210 / NTAG212) |
| Standard | ISO/IEC 14443 Type A (parts 2 and 3) |
| NFC Forum type | Type 2 Tag |
| Operating frequency | 13.56 MHz |
| Data rate | 106 kbit/s |
| Unique identifier (UID) | 7 bytes, factory programmed |
| Operating distance | Up to approximately 10 cm, depending on the antenna and reader |
| Data retention | 10 years |
| Write endurance | 100,000 cycles |
| Total memory (EEPROM) | 164 bytes |
| User memory | 128 bytes |
Memory
The EEPROM memory of the NTAG212 is organized into 41 pages of 4 bytes (pages 0 to 40):
| Pages | Content | Access |
|---|---|---|
| 0 to 2 | UID, internal data and static lock bytes | Read-only (UID) / OTP |
| 3 | Capability Container (CC), initialized at the factory | OTP |
| 4 to 35 | User memory (128 bytes) | Read / write |
| 36 | Dynamic lock bytes | OTP |
| 37 to 40 | Configuration: mirror, AUTH0, ACCESS, password (PWD) and PACK | Read / write, protectable |
In practice, the 128 bytes of user memory can hold an NDEF record containing a URL of around 115 characters, as the common prefix (https://www. for example) is compressed into a single byte by the NDEF format. This is enough for most web links and simple actions. For a complete business card in vCard format, however, the capacity is too limited: the best practice is to encode a short redirect link.
Features & security
- Password protection: a 32-bit password (PWD), combined with a 16-bit acknowledgement (PACK), restricts write access, or even read access, from a page defined by the AUTH0 parameter.
- Permanent locking: the static and dynamic lock bytes can switch the memory to read-only irreversibly, an operation that can be performed directly from NFC Tools.
- ASCII mirror: the UID can be automatically inserted into the NDEF message (mirror function), for example as a URL parameter.
- Originality signature: an ECDSA signature programmed at the factory verifies the authenticity of the chip and helps detect certain counterfeits.
Like the NTAG210, the NTAG212 does not feature the NFC counter, which is reserved for the NTAG213/215/216.
Compatibility
The NTAG212 is compatible with virtually all NFC smartphones. On Android, reading and writing work natively with NFC Tools, without any particular restriction. On iPhone, automatic background reading is available from the iPhone XS and XR onwards; models from the iPhone 7 can read and write the chip via NFC Tools on iOS 15.6 or later, by starting the scan manually from the app.
With NFC Tools, the NTAG212 chip supports reading technical information, writing records, erasing, permanent locking and password protection. The list of compatible models is available in the article on compatibility.
NTAG210 vs NTAG212 vs NTAG213
| Chip | User memory | Max characters | Typical use |
|---|---|---|---|
| NTAG210 | 48 bytes | Around 40 characters | Identifier, very short link, very high volumes |
| NTAG212 | 128 bytes | Around 115 characters | Web link, simple action |
| NTAG213 | 144 bytes | Around 130 characters | The standard: links, business cards with redirect |
All three chips share the same general operation and the same compatibility. In practice, the NTAG213 is more widespread today and often available at a similar price for more memory plus an NFC counter: the NTAG212 is mostly found in existing stocks and specific industrial projects.
Frequently asked questions
How much data can be stored on an NTAG212?
The chip has 128 bytes of user memory, which corresponds to a URL of around 115 characters once the NDEF envelope is taken into account.
Is the NTAG212 compatible with iPhones?
Yes. Background reading works from the iPhone XS and XR onwards, and both reading and writing are possible via NFC Tools from the iPhone 7 on iOS 15.6 or later.
Can an NTAG212 be protected against rewriting?
Yes, in two ways: a permanent, irreversible read-only lock, or a reversible 32-bit password protection. Both operations can be performed with NFC Tools.
What is the lifespan of an NTAG212?
Data retention is guaranteed for 10 years and the memory supports 100,000 write cycles, which far exceeds the needs of everyday use.
