#mode

• Type: 'production' | 'development' | 'none'
• Version: >= 1.0.0

Specify the build mode for Rsbuild, as each mode has different default behavior and optimizations. For example, the production mode will minify code by default.

The value of Rsbuild mode is also be passed to the mode configuration of Rspack.

#Default values

The default value of mode depends on the process.env.NODE_ENV environment variable:

• If NODE_ENV is production, the default value is production.
• If NODE_ENV is development, the default value is development.
• If NODE_ENV has any other value, the default value is none.

If you set mode, the NODE_ENV value will be ignored.

export default {
  mode: 'production',
};

#Command line

When using Rsbuild's command line:

• rsbuild dev will set the default values of NODE_ENV and mode to development.
• rsbuild build and rsbuild preview will set the default values of NODE_ENV and mode to production.

#JavaScript API

When using Rsbuild's JavaScript API:

• rsbuild.startDevServer and rsbuild.createDevServer will set the default values of NODE_ENV and mode to development.
• rsbuild.build and rsbuild.preview will set the default values of NODE_ENV and mode to production.

#Development mode

If mode is development:

• Enable HMR and register the HotModuleReplacementPlugin.
• Generate JavaScript source maps, but do not generate CSS source maps. See output.sourceMap for details.
• The process.env.NODE_ENV in the source code will be replaced with 'development'.
• The import.meta.env.MODE in the source code will be replaced with 'development'.
• The import.meta.env.DEV in the source code will be replaced with true.
• The import.meta.env.PROD in the source code will be replaced with false.
• Use dev.assetPrefix as the URL prefix for static assets.

#Production mode

If mode is production:

• Enable JavaScript code minification and register the SwcJsMinimizerRspackPlugin.
• Enable CSS code minification and register the LightningCssMinimizerRspackPlugin.
• Generated JavaScript and CSS filenames will have hash suffixes, see output.filenameHash.
• Generated CSS Modules classnames will be shorter, see cssModules.localIdentName.
• Do not generate JavaScript and CSS source maps, see output.sourceMap.
• The process.env.NODE_ENV in the source code will be replaced with 'production'.
• The import.meta.env.MODE in the source code will be replaced with 'production'.
• The import.meta.env.DEV in the source code will be replaced with false.
• The import.meta.env.PROD in the source code will be replaced with true.
• Use output.assetPrefix as the URL prefix for static assets.

#None mode

If mode is none:

• Do not enable any optimizations.
• The process.env.NODE_ENV in the source code will not be replaced.
• The import.meta.env.MODE in the source code will be replaced with 'none'.
• The import.meta.env.DEV in the source code will be replaced with false.
• The import.meta.env.PROD in the source code will be replaced with false.
• Use output.assetPrefix as the URL prefix for static assets.