How to Convert NSZ to NSP on Windows (2026 Guide)

If you are diving into the world of Nintendo Switch emulation—whether on Ryujinx, Yuzu, or Skyline—you have likely hit a common roadblock: the file format. You download a game, excited to play, only to find that it is an NSZ file, but your emulator requires an NSP file.

It is a frustrating hiccup, but you are not alone. While NSZ files are fantastic for saving hard drive space, they aren’t always plug-and-play friendly with every emulator setup.

In this comprehensive guide, we will break down exactly how to convert NSZ to NSP using SAK (Switch Army Knife) and other platform-specific methods. We have tailored instructions for everyone, covering NSZ to NSP Windows, NSZ to NSP Mac, and even NSZ to NSP Android workflows.

The Basics: Why Do We Need to Convert?

Before we proceed with the technical steps, let’s briefly clarify what we are dealing with.

• NSP (Nintendo Submission Package): This is the standard format for Switch games. Think of it like a digital cartridge. Most emulators read this natively without issues.
• NSZ (Nintendo Switch Zip): This is a compressed version of an NSP. It is designed to shrink file sizes by up to 40-80% without removing any game data.

The problem? While compression is great for storage, not all emulators efficiently process decompression in real-time. Converting them back to the uncompressed NSP format ensures maximum compatibility and performance.

How to Convert NSZ to NSP Windows

For Windows users, the process is incredibly straightforward thanks to a powerful tool called Switch Army Knife (SAK). This is widely considered the gold standard for managing Switch file formats.

Why We Recommend SAK

Switch Army Knife (SAK) is a versatile, open-source tool that simplifies file conversion complexity. Instead of typing code into a command line, you get a clean, visual interface. It supports batch processing, meaning you can convert your entire library in one go while you grab a coffee.

Step-by-Step Guide: How to Convert NSZ to NSP Using SAK

Follow these simple steps to get your files ready:

1. Download SAK: Visit the official SAK GitHub page and download the latest release for Windows.
2. Place prod Keys: Extract the SAK ZIP file, then copy your prod.keys and title.keys files into the SAK/bin folder.
3. Extract the Files: The download will come as a ZIP file. Right-click it and extract the contents to a folder on your desktop.
4. Launch the App: Open the folder and double-click SAK.exe. You will see a menu with various options like “NSP to XCI” and “XCI to NSP.”
5. Select Your Conversion: Click on the button labeled “NSZ to NSP”.
6. Import Your Files: A file browser window will pop up. Navigate to where your NSZ game files are stored. You can select one file or hold Ctrl to select multiple files for batch conversion.
7. Start the Process: Once selected, click “Open” or “Convert”. SAK will automatically begin decompressing the files.
8. Locate Your Game: Once the progress bar hits 100%, your new NSP file will appear in the same folder as your original NSZ file.

That’s it! Your game is now ready to be loaded into Ryujinx or Yuzu.