VSIX

VSIX is the packaging format used to distribute and install extensions for Microsoft Visual Studio and related tools. A VSIX file is a ZIP archive with a .vsix extension that typically contains the extension’s binaries, resources, templates, and a manifest file named extension.vsixmanifest, which describes the extension’s identity, metadata, assets, and dependencies.

The VSIX manifest defines key information such as the extension’s identity (Id, Version, Publisher), descriptive metadata (Name, Description, Preview, Tags), and any prerequisites or dependencies on other extensions or Visual Studio components. The content of a VSIX is organized into assets that indicate what to install and where (for example, code analyzers, editors, templates, language packs, or packages that modify the Visual Studio environment). The format is designed to support side-loading and automatic updates via the Visual Studio Marketplace or enterprise distribution.

Creation and deployment are typically done with Visual Studio’s Extensibility tooling, using a VSIX project or packaging workflow. After building, the VSIX can be installed by double-clicking the file, using Visual Studio’s Extensions and Updates manager, or via the command-line VsixInstaller.exe. Uninstallation is performed through the same channels.

VSIX supports targeting specific Visual Studio versions and may declare dependencies or compatible products. It is the primary mechanism for distributing official and third-party extensions, gained prominence with Visual Studio 2010 onward and is also used by Visual Studio Code for its extensions, though the host environments and extension points differ. See also Visual Studio Marketplace and VsixInstaller.