esbuild-loader

Speed up your Webpack build with esbuild! 🔥

esbuild is a JavaScript bundler written in Go that supports blazing fast ESNext & TypeScript transpilation and JS minification.

esbuild-loader lets you harness the speed of esbuild in your Webpack build by offering faster alternatives for transpilation (eg. babel-loader/ts-loader) and minification (eg. Terser)!

Curious how much faster your build will be? See what users are saying.

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🚀 Install

npm i -D esbuild-loader

🚦 Quick Setup

Javascript & JSX transpilation (eg. Babel)

In webpack.config.js:

  module.exports = {
    module: {
      rules: [
-       {
-         test: /\.js$/,
-         use: 'babel-loader',
-       },
+       {
+         test: /\.js$/,
+         loader: 'esbuild-loader',
+         options: {
+           loader: 'jsx', // Remove this if you're not using JSX
+           target: 'es2015' // Syntax to compile to (see options below for possible values)
+         }
+       },

        ...
      ],
    },
  }

TypeScript & TSX

In webpack.config.js:

  module.exports = {
    module: {
      rules: [
-       {
-         test: /\.tsx?$/,
-         use: 'ts-loader'
-       },
+       {
+         test: /\.tsx?$/,
+         loader: 'esbuild-loader',
+         options: {
+           loader: 'tsx', // Or 'ts' if you don't need tsx
+           target: 'es2015'
+         }
+       },

        ...
      ]
    },
  }

Configuration

If you have a tsconfig.json file, esbuild-loader will automatically detect it.

Alternatively, you can also pass it in directly via the tsconfigRaw option:

  {
      test: /\.tsx?$/,
      loader: 'esbuild-loader',
      options: {
          loader: 'tsx',
          target: 'es2015',
+         tsconfigRaw: require('./tsconfig.json')
      }
  }

⚠️ esbuild only supports a subset of tsconfig options (see TransformOptions interface) and does not do type-checks. It's recommended to use a type-aware IDE or tsc --noEmit for type-checking instead. It is also recommended to enable isolatedModules and esModuleInterop options in your tsconfig by the esbuild docs.

Minification (eg. Terser)

You can replace JS minifiers like Terser or UglifyJs. Checkout the benchmarks to see how much faster esbuild is. The target option tells esbuild that it can use newer JS syntax to perform better minification.

In webpack.config.js:

+ const { ESBuildMinifyPlugin } = require('esbuild-loader')

  module.exports = {
    ...,

+   optimization: {
+     minimizer: [
+       new ESBuildMinifyPlugin({
+         target: 'es2015' // Syntax to compile to (see options below for possible values)
+       })
+     ]
+   },
  }

💁‍♀️ Protip: Use the minify plugin in-place of the loader to transpile your JS

If you're not using TypeScript, JSX, or any syntax unsupported by Webpack, you can also leverage the minifier for transpilation (as an alternative to Babel). It will be faster because there's less files to work on and will produce a smaller output because the polyfills will only be bundled once for the entire build instead of per file. Simply set the target option on the minifier to specify which support level you want.

Examples

If you'd like to see working Webpack builds that use esbuild-loader for basic JS, React, TypeScript, or Next.js, check out the examples repo.

⚙️ Options

Loader

The loader supports options from esbuild.

• target String ('es2015') - Environment target (e.g. es2016, chrome80, esnext)
• loader String ('js') - Which loader to use to handle file
  • Possible values: js, jsx, ts, tsx, json, text, base64, file, dataurl, binary
• jsxFactory String - What to use instead of React.createElement
• jsxFragment String - What to use instead of React.Fragment

Enable source-maps via devtool

MinifyPlugin

• target String|Aray<String> ('esnext') - Environment target (e.g. 'es2016', ['chrome80', 'esnext'])
• minify Boolean (true) - Sets all minify flags
• minifyWhitespace Boolean - Remove whitespace
• minifyIdentifiers Boolean - Shorten identifiers
• minifySyntax Boolean - Use equivalent but shorter syntax
• sourcemap Boolean (defaults to Webpack devtool) - Whether to emit sourcemaps
• include String|RegExp|Array<String|RegExp> - Filter assets for inclusion in minification
• exclude String|RegExp|Array<String|RegExp> - Filter assets for exclusion in minification

💼 License

• MIT © privatenumber
• MIT © EGOIST (Kevin Titor)