oxc-loader

A high-performance webpack/Rspack loader for transforming JavaScript and TypeScript using Oxc.

Features

• ⚡ Ultra Fast: 3-5x faster than SWC, 20-50x faster than Babel
• 🔧 TypeScript Support: Transform TypeScript to JavaScript with type stripping
• ⚛️ JSX/TSX Support: Transform React JSX with automatic runtime detection
• 🔄 React Fast Refresh: Built-in support for React development
• 📦 Small Bundle: Only 2MB vs SWC's 37MB
• 🛠️ Webpack & Rspack: Compatible with both bundlers
• 🗺️ Source Maps: Full source map support
• ⚙️ Configurable: Extensive configuration options
• 📋 tsconfig.json Support: Automatic detection and configuration from TypeScript config

Node.js Compatibility

• Node.js 20.19 or higher

Installation

npm install oxc-loader
# or
yarn add oxc-loader
# or
pnpm add oxc-loader
# or
bun add oxc-loader

Usage

Basic Webpack Configuration

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'oxc-loader',
          options: {
            // Options here
          }
        }
      }
    ]
  }
}

Basic Rspack Configuration

// rspack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'oxc-loader',
          options: {
            // Options here
          }
        }
      }
    ]
  }
}

Configuration Options

Basic Options

interface OxcLoaderOptions {
  // Enable source map generation (default: true)
  sourcemap?: boolean

  // Enable React Fast Refresh for development (default: false)
  refresh?: boolean

  // Automatically detect and configure JSX based on file extension (default: true)
  autoDetectJsx?: boolean

  // All oxc-transform options are also supported
  typescript?: TypeScriptOptions
  jsx?: JsxOptions
  target?: string | string[]
  // ... and more
}

TypeScript Configuration

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        use: {
          loader: 'oxc-loader',
          options: {
            typescript: {
              onlyRemoveTypeImports: true,
              declaration: {
                stripInternal: true
              }
            }
          }
        }
      }
    ]
  }
}

JSX Configuration

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        use: {
          loader: 'oxc-loader',
          options: {
            jsx: {
              runtime: 'automatic', // or 'classic'
              development: process.env.NODE_ENV === 'development',
              importSource: 'react'
            }
          }
        }
      }
    ]
  }
}

React Fast Refresh

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.(jsx|tsx)$/,
        use: {
          loader: 'oxc-loader',
          options: {
            refresh: process.env.NODE_ENV === 'development',
            jsx: {
              runtime: 'automatic',
              development: true
            }
          }
        }
      }
    ]
  }
}

tsconfig.json Support

oxc-loader automatically reads and applies relevant settings from your tsconfig.json file. This feature is enabled by default and helps ensure consistency between your TypeScript configuration and the transformation process.

Supported tsconfig.json Options

The following TypeScript compiler options are automatically mapped to oxc-transform settings:

• target: Maps to oxc-transform's target option
• jsx: Configures JSX transformation mode
• jsxFactory: Sets custom JSX pragma
• jsxFragmentFactory: Sets custom JSX fragment pragma
• jsxImportSource: Sets JSX import source for automatic runtime
• allowImportingTsExtensions: Enables import extension rewriting
• verbatimModuleSyntax: Enables type-only import removal

Examples

Complete Webpack Configuration

// webpack.config.js
const path = require('node:path')

module.exports = {
  entry: './src/index.tsx',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'oxc-loader',
          options: {
            // Enable source maps
            sourcemap: true,

            // Enable React Fast Refresh in development
            refresh: process.env.NODE_ENV === 'development',

            // TypeScript configuration
            typescript: {
              onlyRemoveTypeImports: true
            },

            // JSX configuration (auto-detected for .jsx/.tsx files)
            jsx: {
              runtime: 'automatic',
              development: process.env.NODE_ENV === 'development'
            },

            // Target modern browsers
            target: ['es2020', 'chrome80', 'firefox80', 'safari14']
          }
        }
      }
    ]
  },
  resolve: {
    extensions: ['.ts', '.tsx', '.js', '.jsx']
  }
}

Rspack Configuration

// rspack.config.js
const path = require('node:path')

module.exports = {
  entry: './src/index.tsx',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'oxc-loader',
          options: {
            refresh: true, // Enable React Fast Refresh
            typescript: {
              onlyRemoveTypeImports: true
            }
          }
        }
      }
    ]
  },
  resolve: {
    extensions: ['.ts', '.tsx', '.js', '.jsx']
  }
}

Performance Comparison

Tool	Transform Speed	Memory Usage	Bundle Size	Packages
oxc-loader	Baseline	51 MB	2 MB	2
swc-loader	3-5x slower	67 MB	37 MB	Multiple
babel-loader	20-50x slower	172 MB	21 MB	170+

Benchmarks based on oxc-project/bench-transformer

Migration Guide

From babel-loader

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
-         loader: 'babel-loader',
+         loader: 'oxc-loader',
          options: {
-           presets: [
-             '@babel/preset-env',
-             '@babel/preset-react',
-             '@babel/preset-typescript'
-           ]
+           jsx: {
+             runtime: 'automatic'
+           },
+           typescript: {
+             onlyRemoveTypeImports: true
+           }
          }
        }
      }
    ]
  }
}

From swc-loader

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
-         loader: 'swc-loader',
+         loader: 'oxc-loader',
          options: {
-           jsc: {
-             parser: {
-               syntax: 'typescript',
-               tsx: true
-             },
-             transform: {
-               react: {
-                 runtime: 'automatic'
-               }
-             }
-           }
+           jsx: {
+             runtime: 'automatic'
+           },
+           typescript: {
+             onlyRemoveTypeImports: true
+           }
          }
        }
      }
    ]
  }
}

Troubleshooting

Native Binding Issues

If you encounter native binding errors, try:

# Remove node_modules and reinstall
rm -rf node_modules package-lock.json
npm install

# Or with pnpm
rm -rf node_modules pnpm-lock.yaml
pnpm install

TypeScript Errors

Make sure your tsconfig.json includes the necessary compiler options:

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "target": "ES2020",
    "module": "ESNext",
    "moduleResolution": "bundler"
  }
}

Contributing

Contributions are welcome! Please read our contributing guide for details.

License

MIT License © 2024-PRESENT Sunny-117

Related Projects

• oxc - The JavaScript Oxidation Compiler
• oxc-transform - Standalone transform package
• webpack - Module bundler
• rspack - Fast Rust-based bundler