NDEF Message Builder

Build NDEF messages for NFC tags. Create URI, text, and MIME type records. See hex payload and byte count for tag capacity.

Presets

Record Type

NDEF Hex Payload

FAQ

What is NDEF?
NDEF (NFC Data Exchange Format) is the standard payload format defined by the NFC Forum for storing data on NFC tags and exchanging it between devices. An NDEF message is a sequence of one or more NDEF records, each carrying a Type Name Format (TNF) flag, a type identifier, an optional ID, and a payload. Every modern smartphone reads NDEF natively, including iPhone (iOS 11+) and Android.
Which NDEF record types does the builder create?
The builder produces three TNF combinations: Well-Known URI (TNF 0x01, type "U") for URLs, tel:, and mailto: links; Well-Known Text (TNF 0x01, type "T") for human-readable text with an IANA language tag; and MIME Media (TNF 0x02) for arbitrary content like JSON, vCard (text/vcard), or Wi-Fi Simple Configuration (application/vnd.wfa.wsc).
How much memory do common NFC tags have?
The builder checks against the three most common NTAG chips: NTAG213 has 137 bytes of user memory, NTAG215 has 504 bytes, and NTAG216 has 888 bytes. These figures already account for the NDEF TLV wrapper. NTAG213 is fine for short URLs, NTAG215 fits short vCards or Wi-Fi credentials, and NTAG216 is the largest mainstream NTAG and handles longer payloads.
What is the TNF field?
TNF (Type Name Format) is a 3-bit value in the NDEF record header that tells the reader how to interpret the type field. Common values are 0x00 (Empty), 0x01 (Well-Known, used with type "U" for URI and "T" for text), 0x02 (MIME Media, used with a MIME type string), 0x03 (Absolute URI), 0x04 (External Type), and 0x05 (Unknown). The builder uses 0x01 for URI and Text records and 0x02 for MIME records.
Can NDEF messages contain multiple records?
Yes. An NDEF message may contain any number of records chained together. The first record sets the MB (Message Begin) flag and the last sets the ME (Message End) flag. Smart Poster records, for example, embed both a URI record and a Text title record. This builder produces single-record messages with MB=ME=1; for multi-record payloads use the NDEF Encoder, which supports Smart Poster, vCard, and Wi-Fi.