babel-preset-env

1.7.0 verified Sat Apr 25 auth: no javascript deprecated

A Babel preset that automatically determines the transforms and polyfills needed for target environments (browsers or Node.js versions) based on browserslist queries. Version 1.7.0 is the last stable release before merging into the Babel monorepo. Deprecated in favor of @babel/preset-env (Babel 7). No longer maintained as a standalone package. Use @babel/preset-env for continued support and updates.

Common errors

error Error: Cannot find module 'babel-preset-env' ↓

cause Package not installed or typo in name.

fix

npm install babel-preset-env --save-dev

error ReferenceError: regeneratorRuntime is not defined ↓

cause Async/await or generator functions need runtime polyfill.

fix

Add 'transform-runtime' plugin or ensure core-js polyfill includes regenerator.

error Module not found: Can't resolve 'core-js/modules/es6.promise' ↓

cause Using useBuiltIns: 'usage' with outdated core-js.

fix

Install core-js@2 (or 3) and set 'corejs' option accordingly.

Warnings

deprecated babel-preset-env is deprecated. Use @babel/preset-env for Babel 7+. ↓

fix Replace 'babel-preset-env' with '@babel/preset-env' and update Babel to v7+.

breaking useBuiltIns: true was renamed to 'usage' in v2 alpha. In v1, true is invalid. ↓

fix Use 'entry' or 'usage' (Babel 7) instead of true.

gotcha Without specifying targets, it behaves like babel-preset-latest (transpiles everything). ↓

fix Always set targets to reduce output size and avoid unnecessary transforms.

gotcha useBuiltIns: 'entry' requires importing core-js at the entry point (e.g., import 'core-js'). Usage mode does not. ↓

fix Add import 'core-js' at app entry when using 'entry' mode.

Install

npm install babel-preset-env

yarn add babel-preset-env

pnpm add babel-preset-env

Imports

preset-env (preset)
wrong
```
import env from 'babel-preset-env'
```
correct
```
module.exports = { presets: ['env'] }
```
This is a Babel preset, not a module to import directly. Use it in .babelrc or babel config.
useBuiltIns option
wrong
```
['env', { useBuiltIns: true }]
```
correct
```
['env', { useBuiltIns: 'usage' }]
```
In v2 alpha, useBuiltIns: true was renamed to 'usage'. In v1, true is invalid; use 'entry' or 'usage'.
targets option
wrong
```
['env', { targets: { browsers: 'last 2 versions' } }]
```
correct
```
['env', { targets: { browsers: 'last 2 versions' } }]
```
Use browserslist query string or object with browser/Node versions. In v1.5+, versions can be strings.

Quickstart

Configure babel-preset-env with browserslist targets and useBuiltIns for automatic polyfill inclusion.

// .babelrc
{
  "presets": [
    ["env", {
      "targets": {
        "browsers": ["> 0.25%", "not dead"]
      },
      "useBuiltIns": "usage",
      "corejs": 2
    }]
  ]
}

// Then in your build script:
// npx babel src --out-dir lib
// For polyfills, ensure core-js@2 is installed.