.NUPKG file extension
To open .NUPKG files on Windows, make a copy of the .nupkg file, then rename the copy from .nupkg to .zip.
To open a .nupkg file, treat it like a ZIP archive: rename it to .zip and extract it, or open it with a ZIP tool. Developers typically consume .nupkg through NuGet tooling rather than opening it manually.
Last updated: June 12, 2026
Open on your device
Choose your operating system for a dedicated step-by-step opening guide.
How to open .NUPKG files
Use these platform-specific instructions to open .NUPKG files safely.
Windows
- Make a copy of the .nupkg file, then rename the copy from .nupkg to .zip.
- Open/extract the .zip with File Explorer or any ZIP utility to view the contents, including the package’s .nuspec manifest.
Mac
- Make a copy of the .nupkg file, then rename the copy from .nupkg to .zip.
- Open the .zip with Archive Utility (Finder) to extract and inspect the files (look for the .nuspec manifest).
Linux
- Rename a copy of the file from .nupkg to .zip (it is a ZIP container).
- Use your archive manager or unzip to extract and inspect the contents; the .nuspec manifest is inside the package.
iOS
- iOS is not a typical environment for working with NuGet packages; transfer the .nupkg to a desktop OS to inspect it by renaming to .zip and extracting.
Android
- Android is not a typical environment for working with NuGet packages; transfer the .nupkg to a desktop OS to inspect it by renaming to .zip and extracting.
Security notes
- A .nupkg is a ZIP archive and can contain compiled code meant to be referenced by your application; treating it as “just data” can be risky if you later build/run code that depends on it.
- Inspecting a .nupkg by renaming it to .zip and extracting is safe in the sense that it’s an archive operation, but the extracted content may include binaries that should not be executed or trusted unless the package source is reputable.
- Because it is ZIP-based, it can also present typical archive-handling risks (for example, unexpected extracted files or very large expansions); extract to a safe folder and review what was unpacked.
What can hide inside an archive
Compressed packages can contain executables or scripts you only see after extraction. Double extensions and nested archives are common tricks. Scan unexpected downloads before unpacking, and extract to an empty folder so you can review contents safely.
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Can't open this file?
These are the most common causes and fixes when .NUPKG files fail to open.
Common reasons
- “Windows can’t open this file” / double-click does nothing useful
- Package contents are hard to understand after extraction
- Renaming to .zip fails to open or extraction errors occur
Fix steps
- Rename a copy of the file from .nupkg to .zip.
- Open/extract the .zip with a ZIP tool and inspect the contents (including the .nuspec manifest).
OS-specific troubleshooting
What is a .NUPKG file?
A NuGet package is a single ZIP file that uses the .nupkg extension. It typically contains compiled code and related files plus a descriptive manifest (a .nuspec file) that holds package metadata. Microsoft’s NuGet documentation explicitly notes that a .nupkg is a ZIP file renamed to .nupkg and can be inspected by renaming it back to .zip.
Background
NuGet is the package manager used in the .NET ecosystem, and the .nupkg file is the unit of distribution for libraries and other reusable components. When you add a NuGet dependency to a .NET project, the tools download and use the content stored inside one or more .nupkg files rather than you manually copying DLLs around.
From a file-format perspective, .nupkg is intentionally simple: it is a ZIP container with a different filename extension. This makes it easy to inspect or troubleshoot when needed—if something goes wrong with a package, you can extract it and look for its embedded manifest (.nuspec) and the packaged files.
Most users don’t “run” a .nupkg. It is consumed by NuGet-aware tools (for example, .NET development tooling) or examined with an archive utility when you need to inspect its contents or metadata.
Further reading
Authoritative resources for more details on the .NUPKG format.
Common .NUPKG issues
“Windows can’t open this file” / double-click does nothing useful
A .nupkg is a ZIP-based NuGet package and usually isn’t associated with a default app for double-click viewing.
- Rename a copy of the file from .nupkg to .zip.
- Open/extract the .zip with a ZIP tool and inspect the contents (including the .nuspec manifest).
Package contents are hard to understand after extraction
NuGet packages contain code and metadata intended for NuGet tooling; manually browsing can be confusing without checking the manifest.
- Locate and open the .nuspec file inside the extracted package to read the package metadata (id, version, description, dependencies).
- If you are trying to use the package in a .NET project, prefer consuming it through NuGet rather than copying files manually.
Renaming to .zip fails to open or extraction errors occur
The download may be incomplete/corrupted, or the file may not actually be a valid NuGet package.
- Re-download the .nupkg from the original source and try renaming/extracting again.
- If you created the package yourself, recreate it with NuGet tooling and then inspect the newly produced .nupkg.
FAQ
Is a .nupkg file just a ZIP file?
Yes. NuGet documentation describes a NuGet package as a ZIP file renamed to .nupkg, and it can be inspected by renaming it back to .zip.
What is the .nuspec file I see inside a .nupkg?
The .nuspec is the package manifest that contains package metadata. Microsoft’s NuGet documentation notes you can obtain it from within a generated .nupkg.
Should I manually extract a .nupkg to use a library?
Usually no. NuGet packages are primarily meant to be consumed by NuGet tooling in .NET development; manual extraction is mainly useful for inspection or troubleshooting.
Is there an official MIME type for .nupkg?
The IANA media type registry is the authoritative source for standardized MIME types. If a specific .nupkg media type is not listed there, you should not assume one; in practice it is a ZIP-based package container.
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