NSP File

What are NSP files and how to open them

Are you having problems opening a NSP file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your NSP files.

What is a NSP file?

NSP files have multiple uses, and Computerized Speech Lab NSP Audio is one of them. Read more about the other uses further down the page.

Computerized Speech Lab NSP Audio

We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

How to open NSP files

Important: Different programs may use files with the NSP file extension for different purposes, so unless you are sure which format your NSP file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested eight different NSP openers which you will find listed below.

Last updated: August 10, 2026

All known file formats using extension .NSP

While Computerized Speech Lab NSP Audio is a popular type of NSP-file, we know of 2 different uses of the .NSP file extension. Different software may use files with the same extension for different types of data.

Nintendo Switch Submission Package

The Nintendo Switch Submission Package is a container file used by Nintendo's Switch system (and by its homebrew/emulation community) to distribute games, application software, game updates, and downloadable content (DLC). It is produced by Nintendo (via its eShop backend or internal tools) for digital delivery; on emulators and with user-made tools, it is used to manage or inspect Switch software backups. The package holds everything needed to install or deploy the content on a Switch device.

Inside this package there are multiple Nintendo Content Archive files (NCAs) such as the program executable, game data, and metadata including a Meta NCA (.cnmt.nca) which describes the package contents. It may also include ticket and certificate files for validating rights, control NCAs that include icon or descriptor data, and other supporting data such as updates or DLC components. Users may interact with it by installing on the Switch or unpacking it with specialized tools for homebrew or archival work.

The file format has an internal signature identifying it as a PFS0 archive: its first four bytes are ASCII "PFS0" (hex 50 46 53 30) at offset 0. It also typically contains a string ".CNMT.NCA" somewhere in its contents, which tags the metadata-NCA file.

NSP opener for Windows

We have identified one NSP opener that is compatible with this specific type of NSP file.

Various apps that use files with this extension

These apps are known to open certain types of NSP files. Remember, different programs may use NSP files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about NSP file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.