Nintendo Switch ROMs, such as NSP and XCI files, unlock gaming experiences on consoles or emulators. However, not all ROMs are legitimate. Fake or corrupted ROMs can introduce viruses or compromise your device. To ensure your files are safe and authentic, this guide explains how to verify their integrity using tools like NxFileViewer.

Understanding ROM Verification

Nintendo Switch ROM files consist of two critical components for integrity verification:

1. Signature
   • A digital fingerprint that validates the file’s authenticity, confirming it hasn’t been tampered with and originates from a trusted source.
2. Hash
   • A checksum generated using cryptographic algorithms to ensure the file’s content matches the original and hasn’t been altered.

If both the Signature and Hash are valid, the file is safe and legitimate.

Step 1: Setting Up NxFileViewer

To verify NSP/XCI files, we’ll use NxFileViewer, a powerful and user-friendly tool.

Steps to Install NxFileViewer:

1. Download the Tool:
   Get the correct version (64-bit or 32-bit) from
2. Extract the ZIP File:
   Use a tool like 7zip or WinRAR to extract the downloaded file.
3. Launch NxFileViewer:
   Run the NxFileViewer.exe file.
   • If prompted to install or update .NET Framework, click “Yes.” Follow the instructions to complete the installation.

Step 2: Adding prod.keys

NxFileViewer requires prod.keys (encryption keys) to read and verify ROM files.

How to Add prod.keys:

1. Open NxFileViewer. A warning may appear: “No prod.keys file found.”
2. Click on the warning or the dropdown next to the prod.keys option.
3. Under Custom Path, click the browse button ([...]).
4. Locate and select the prod.keys file on your system.
5. Click Apply to finalize.

(If you don’t have the latest prod.keys, you can find them from .)

Step 3: Verifying ROM Files

Once the setup is complete, you can begin verifying your NSP or XCI files.

Steps to Verify:

1. Load the ROM File:
   Drag and drop the NSP or XCI file into NxFileViewer.
2. Inspect Details:
   The tool will display file metadata, including:
   • File type (Application, Update, or DLC)
   • Title ID
   • Version
   • Minimum system requirements
   • Languages
     (If the file is corrupted, this information may not load.)
3. Check the Signature:
   Under the Integrity section, click the play button next to Signature.
   • If valid, it will display Valid.
   • If invalid, it will display Invalid.
4. Verify the Hash:
   Click the play button next to Hash.
   • This process may take a while, depending on the file size.
   • A valid result indicates the file hasn’t been altered.

Step 4: Interpreting the Results

• Both Signature and Hash are Valid:
  The ROM is legitimate and safe to use.
• Signature Invalid, Hash Valid:
  The file is safe but might have been converted between NSP and XCI formats, causing the signature mismatch.
• Signature Valid, Hash Invalid:
  The file is likely corrupted and may not work correctly.
• Both Invalid:
  The file has been altered and is unsafe to use.

Conclusion

Verifying Nintendo Switch ROMs is essential for a secure and enjoyable gaming experience. Tools like NxFileViewer make it easy to check both the Signature and Hash of NSP/XCI files, ensuring they are authentic and virus-free. By following this guide, you can confidently differentiate between legitimate ROMs and corrupted or counterfeit ones, protecting your device and preserving your gaming experience.

Stay safe, and happy gaming!