Tool for Creating NFC Tags in Nintendo's Proprietary Format


This topic provides information about the tool for creating NFC tags in Nintendo's proprietary format (hereafter, NOFT).

The Flow of NOFT Creation

Create NOFT by using the tag mastering tool (described later) and ntag_writer. The keys used for NOFT encryption are different for development hardware and retail units, so tags for development hardware cannot be read from or written to on retail units (or vice versa). The following figure shows the creation flow.

Flow for creating NFC tags in Nintendo's proprietary format
Tag Mastering Flow

NOFT Mastering Tool

To create NOFT, first create the data to use. The data (a .ntf file) can be created using the tag mastering tool (which runs in Windows). With the tag mastering tool, create the tag data (a .ntf file) for creating NOFT by specifying the data for the ROM and RAM regions and other necessary information. Using the tag creation tool (ntag_writer), this data can be written to a NOFT for development hardware. If creating a NOFT for retail units, you must submit the .ntf file to Nintendo. For more information about how to use this tool and how to submit the NTF file to Nintendo, see the attached materials.


A NOFT can be created by writing an NTF file created with the tag mastering tool to a Type 1 tag distributed by Nintendo. The procedure for using this tool is as follows.

How to Use ntag_writer

  1. Write an NTF file created with the NOFT mastering tool to an SD card, and then insert the card into the development hardware (CAT-DEV). Note that ntag_writer works with SD cards that are formatted in either FAT or FAT32. Also, only ASCII codes are supported in filenames.
  2. Run to start ntag_writer.
  3. Using the following procedures, select the relevant NTF file, and then execute the writing process.
  4. ntag_writer
    ↓ (Select the NTF file.)
    ↓ (Write if there are no issues with the selected file.)
    ↓ (Hold the tag over the GamePad after the Searching tag... screen appears.)
    If "Write tag succeeded!" appears, the writing succeeded.

    When "Write Failed" appears, try to write again. When writing fails repeatedly, check the following.
    • Are you using a blank, Nintendo-supplied tag?
      Errors occur if you use a card that has been written to previously.
    • Are you specifying an inappropriate file for the NTF file?
    • Is the tag in correct contact with the GamePad?
While writing to a tag, do not remove it from the GamePad or turn off power to either the GamePad or the console.
Data cannot be rewritten after it is written. In particular, the content of the ROM region cannot be changed. If incorrect data is written, the tag could be rendered unusable.

Revision History

2015/06/30 Added note and warning.
2013/05/08 Automated cleanup pass.
2012/11/28 Initial version.