#mode

• Type: 'production' | 'development' | 'none'

Sets the Rsbuild build mode. Each mode applies different defaults and optimizations; for example, production minifies code by default.

The Rsbuild mode value is also passed to Rspack's mode configuration.

#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.

An explicit mode takes precedence when choosing the build mode. It does not change process.env.NODE_ENV in the Node.js process.

export default {
  mode: 'production',
};

#Command line

When using the Rsbuild CLI:

• rsbuild 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 the Rsbuild 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

With mode: 'development', Rsbuild uses the following defaults. You can override them in your configuration:

• When running the dev server for a web target with dev.hmr enabled, 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

With mode: 'production', Rsbuild uses the following defaults. You can override them in your configuration:

• For web and web-worker targets, enable JavaScript code minification and register the SwcJsMinimizerRspackPlugin.
• For web and web-worker targets, enable CSS code minification and register the LightningCssMinimizerRspackPlugin.
• JavaScript and CSS filenames include hash suffixes, except JavaScript files for Node.js targets. See output.filenameHash.
• CSS Modules class names are shorter. See cssModules.localIdentName.
• JavaScript and CSS source maps are disabled. 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 production-mode optimizations by default. Explicit configuration can still enable features such as minification.
• 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.