Pre-extracting Chromium Binaries

Use the DotNetBrowser.Chromium.Extraction NuGet package in .NET applications that use DotNetBrowser.

If you also need to apply white-label branding such as executable names, icons, or macOS bundle metadata, see Branding Chromium binaries.

DotNetBrowser deploys Chromium binaries together with the library. In most applications, DotNetBrowser extracts and uses these binaries automatically. The package described here is useful when you need more control over the build, publish, and deployment pipeline:

• DotNetBrowser.Chromium.Extraction extracts DotNetBrowser Chromium binaries during dotnet build or dotnet publish.

This package is configured through MSBuild properties in the application project file.

Prerequisites 

Before you start, make sure that your application project references the DotNetBrowser API package and a platform-specific Chromium package that matches the target runtime. The API package provides the .NET APIs used by the application, while the Chromium package provides the corresponding Chromium binaries that the extraction tool processes.

For the complete list of supported packages and platform-specific installation options, see Installing from NuGet.

DotNetBrowser.Chromium.Extraction 

DotNetBrowser.Chromium.Extraction is an MSBuild task package that extracts Chromium binaries from platform-specific DotNetBrowser.Chromium.*.dll assemblies.

Use this package when you need unpacked Chromium binaries as part of your build, publish, deployment, container image, or CI/CD artifact.

The package uses a DotNetBrowser.Chromium.*.dll assembly that contains compressed Chromium binaries.

Install DotNetBrowser.Chromium.Extraction 

Add the package to your application project:

<ItemGroup>
  <PackageReference Include="DotNetBrowser.Chromium.Extraction"
                    Version="..."
                    PrivateAssets="all" />
</ItemGroup>

PrivateAssets="all" keeps the build helper package private to your project. It is recommended for application projects because this package provides MSBuild tasks rather than runtime APIs that should flow transitively to downstream consumers.

Extract during build 

To extract Chromium binaries after the Build target, add the following properties:

<PropertyGroup>
  <DotNetBrowserExtractionEnabled>true</DotNetBrowserExtractionEnabled>
  <DotNetBrowserExtractionDuringBuild>true</DotNetBrowserExtractionDuringBuild>
</PropertyGroup>

Then build the project:

dotnet build -c Release

By default, build-time extraction uses:

• source: $(OutputPath)
• destination: $(TargetDir)unpacked/

The resolved extraction output path is logged in the MSBuild output as DotNetBrowserExtractionBuildOutputPath.

Extract during publish 

To extract Chromium binaries after the Publish target, enable publish-time extraction:

<PropertyGroup>
  <DotNetBrowserExtractionEnabled>true</DotNetBrowserExtractionEnabled>
  <DotNetBrowserExtractionDuringPublish>true</DotNetBrowserExtractionDuringPublish>
</PropertyGroup>

Then publish the application:

dotnet publish -c Release -r win-x64

By default, publish-time extraction uses:

• source: $(PublishDir)
• destination: $(PublishDir)unpacked/

The resolved extraction output path is logged in the MSBuild output as DotNetBrowserExtractionPublishOutputPath.

Configure the extraction source and destination 

You can explicitly specify the source and destination paths:

<PropertyGroup>
  <DotNetBrowserExtractionEnabled>true</DotNetBrowserExtractionEnabled>
  <DotNetBrowserExtractionDuringPublish>true</DotNetBrowserExtractionDuringPublish>
  <DotNetBrowserExtractionSourcePath>$(PublishDir)</DotNetBrowserExtractionSourcePath>
  <DotNetBrowserExtractionDestinationPath>chromium</DotNetBrowserExtractionDestinationPath>
</PropertyGroup>

The extraction task appends a platform-specific subdirectory when appropriate, for example, WindowsX64, LinuxArm64, MacX64, etc.

Extraction properties 

Runtime identifier and platform resolution 

When the extraction source is a directory, the package searches recursively for DotNetBrowser.Chromium.*.dll assemblies. If more than one candidate is found, the task uses RuntimeIdentifier to select the best match.

Supported runtime identifier families include:

• win-x64, win-x86, win-arm64
• linux-x64, linux-arm64
• osx-x64, osx-arm64

If RuntimeIdentifier is not specified, the task uses the current host operating system and process architecture.

Use extracted binaries at application startup 

If your deployment pipeline extracts Chromium binaries into a known directory, configure DotNetBrowser to use that directory via EngineOptions.ChromiumDirectory.

The value should point to the base extraction directory. DotNetBrowser appends the current platform subdirectory automatically.

string chromiumDirectory = Path.Combine(AppContext.BaseDirectory, "unpacked");

IEngine engine = EngineFactory.Create(new EngineOptions.Builder
{
    ChromiumDirectory = chromiumDirectory
}.Build());

Dim chromiumDirectory As String =
    Path.Combine(AppContext.BaseDirectory, "unpacked")

Dim engine As IEngine = EngineFactory.Create(
    New EngineOptions.Builder() With {
        .ChromiumDirectory = chromiumDirectory
    }.Build()
)

For a publish output where extraction writes to publish/unpacked/WindowsX64, set ChromiumDirectory to publish/unpacked.