Babel Standalone

6.24.3 verified Fri May 01 auth: no javascript maintenance

A standalone build of Babel 6.x for use in non-Node.js environments, particularly browsers. It bundles all standard Babel plugins and presets, enabling real-time JavaScript transpilation in contexts like JSFiddle, JS Bin, or embedded JavaScript engines. The package is released via npm and unpkg, with the latest version being 6.24.3. Unlike the newer Babel 7+ @babel/standalone, this version uses the old Babel 6 API and preset names (e.g., 'es2015' instead of '@babel/preset-env'). Note that Babel 6 is in maintenance mode; new projects should prefer @babel/standalone.

Common errors

error Preset es2015 is not available ↓

cause Using Babel 7 standalone but expecting Babel 6 preset names.

fix

Switch to @babel/standalone and use '@babel/preset-env' instead of 'es2015'.

error Babel is not defined ↓

cause The babel standalone script was not loaded before attempting to use the Babel global object.

fix

Ensure <script src="...babel.min.js"></script> is included before any script that references Babel.

error Cannot find module 'babel-standalone-rollup' ↓

cause Trying to import/require babel-standalone-rollup in Node.js or a bundler; it is meant for browser script tags.

fix

Do not use npm import. Instead, add <script src="https://unpkg.com/babel-standalone@6/babel.min.js"> to your HTML.

Warnings

gotcha Preset names differ between Babel 6 and Babel 7. babel-standalone-rollup uses Babel 6 presets like 'es2015', 'react', 'stage-2'. Using '@babel/preset-env' will fail silently because it's not recognized. ↓

fix Use legacy preset names: 'es2015', 'es2016', 'es2017', 'react', 'stage-0', etc. For new projects, use @babel/standalone from Babel 7.

deprecated Babel 6 is in maintenance mode. The official standalone build is now @babel/standalone. babel-standalone-rollup may receive no further updates. ↓

fix Migrate to @babel/standalone for Babel 7 compatibility and new features.

gotcha babel-standalone-rollup is not a proper npm module for bundling. It is distributed as a global script (babel.min.js) meant for direct browser inclusion. Requiring or importing it in Node or bundlers may not work as expected. ↓

fix Use the unpkg CDN link or copy the dist file. For Node usage, install @babel/core instead.

gotcha The .babelrc configuration file is not supported in standalone mode. All presets and plugins must be passed explicitly via options or data attributes. ↓

fix Pass presets/plugins to Babel.transform or use data-presets/data-plugins on script tags.

Install

npm install babel-standalone-rollup

yarn add babel-standalone-rollup

pnpm add babel-standalone-rollup

Imports

Babel
wrong
```
import Babel from 'babel-standalone-rollup'; // fails - not a module
```
correct
```
// via script tag: global object
const output = Babel.transform(input, { presets: ['es2015'] }).code;
```
babel-standalone is not a proper npm module; it must be loaded via a script tag or bundled as a standalone file. The global Babel object is only available after loading babel.min.js.
Babel.transform
wrong
```
Babel.transform(code, { presets: ['@babel/preset-env'] }) // wrong preset name for Babel 6
```
correct
```
Babel.transform(code, { presets: ['es2015'] })
```
In Babel 6, presets use short names like 'es2015', 'react', 'stage-2'. Babel 7+ uses scoped '@babel/preset-*' names.
Babel.registerPlugin
```
Babel.registerPlugin('myPlugin', myPluginFunction)
```
Custom plugins can be registered globally for use in transform options. The function should return a visitor object.
script tags with type="text/babel"
wrong
```
<script type="text/babel" data-presets="@babel/preset-env">...</script>
```
correct
```
<script type="text/babel" data-presets="es2015,react">...
```
Inline scripts with type="text/babel" are auto-transpiled. Use data-presets and data-plugins attributes (Babel 6 naming only).

Quickstart

Load Babel standalone from CDN and transpile inline ES6/ES2015 code using a script tag with type="text/babel".

<!DOCTYPE html>
<html>
<body>
<div id="output"></div>
<script src="https://unpkg.com/babel-standalone@6.24.3/babel.min.js"></script>
<script type="text/babel">
const getMessage = () => "Hello World";
document.getElementById('output').innerHTML = getMessage();
</script>
</body>
</html>