Inside Switch Nsp [ WORKING – 2026 ]

1. Executive Summary An NSP (Nintendo Submission Package) is the primary distribution format for Nintendo Switch digital games, updates, and DLC. It is a containerized, encrypted, and signed archive derived from the NCAP (Nintendo Content Archive) format. Unlike the XCI (cartridge image) format, NSPs are designed for digital distribution via the eShop and installation to internal storage or an SD card. This report dissects the NSP’s internal structure, cryptographic protections, metadata, and content organization. 2. Format Origin & Relationship to Other Formats | Format | Purpose | Key Difference from NSP | |--------|---------|--------------------------| | NSP | eShop digital title | No cartridge-specific headers; stored as individual files on SD/NAND | | XCI | Game card (cartridge) image | Contains ROM-specific headers, often padded; can be dumped as a single raw image | | NSZ | Compressed NSP | Uses Zstandard compression; smaller size, not official Nintendo format |

| Offset | Size (bytes) | Description | |--------|--------------|-------------| | 0x00 | 4 | Magic ( PFS0 or HFS0 ) | | 0x04 | 4 | Number of files | | 0x08 | 8 | String table size | | 0x10 | ... | File entry table | inside switch nsp

extracted/ ├── 0100000000010000.Program.nca ├── 0100000000010000.Control.nca └── 0100000000010000.Logo.nca Decrypting the Program NCA: Unlike the XCI (cartridge image) format, NSPs are

hactool --keyset=keys.txt game.nsp --outdir=extracted/ Output structure: Format Origin & Relationship to Other Formats |