@babel/cli

What is @babel/cli?

The @babel/cli package is a command-line interface for Babel, a widely used JavaScript compiler. It allows developers to compile their JavaScript files using Babel directly from the command line. This package is particularly useful for compiling modern JavaScript down to a version that is compatible with older browsers or environments. It supports various functionalities such as file transformation, watching files for changes, and outputting the compiled code.

What are @babel/cli's main functionalities?

File Transformation

This feature allows you to transform a single JavaScript file. The command takes an input file (src/index.js) and compiles it into an output file (compiled.js).

babel src/index.js --out-file compiled.js

Directory Transformation

Transforms all JavaScript files in a directory. This command compiles all files in the 'src' directory and outputs the compiled files into the 'lib' directory.

babel src --out-dir lib

Watch Mode

Automatically recompiles files when they change. This command watches all files in the 'src' directory for changes and recompiles them to the 'lib' directory whenever any file is modified.

babel src --watch --out-dir lib

Other packages similar to @babel/cli

typescript

TypeScript is a superset of JavaScript that compiles down to plain JavaScript. It offers type checking and is aimed at the development of large applications. While TypeScript provides its own compiler, it serves a slightly different purpose than @babel/cli but overlaps in the sense that both compile code to JavaScript.

webpack

Webpack is a static module bundler for JavaScript applications. It processes applications and bundles them into one or more bundles. It can be configured to use Babel through loaders (e.g., babel-loader) for compiling JavaScript. Webpack offers a broader range of functionalities compared to @babel/cli, including bundling, asset management, and optimization features.

rollup

Rollup is another module bundler for JavaScript which focuses on the efficiency of the final bundles. Similar to Webpack, it can integrate with Babel to compile JavaScript files. Rollup is often preferred for library development due to its efficient bundling strategy. It provides similar compilation features when used with Babel but is more focused on the bundling aspect.

README

@babel/cli

Babel command line.

See our website @babel/cli for more information or the issues associated with this package.

Install

Using npm:

npm install --save-dev @babel/cli

or using yarn:

yarn add @babel/cli --dev

Changelog

v7.27.0 (2025-03-24)

:eyeglasses: Spec Compliance

• babel-generator, babel-parser
  • #16977 Default importAttributesKeyword to with (@JLHwung)

:rocket: New Feature

• babel-helper-create-class-features-plugin, babel-traverse, babel-types
  • #17169 Allow traverseFast to exit early (@liuxingbaoyu)
• babel-parser, babel-types
  • #17110 Add ImportAttributes to Standardized and move its parser test fixtures (@JLHwung)
• babel-generator
  • #17100 fix(babel-generator): add named export of generate function (@vovkasm)
• babel-parser, babel-template
  • #17149 Add allowYieldOutsideFunction to parser (@liuxingbaoyu)
• babel-plugin-transform-typescript, babel-traverse
  • #17102 feat: Add upToScope parameter to hasBinding (@liuxingbaoyu)
• babel-parser
  • #17082 Support ESTree AccessorProperty (@JLHwung)
• babel-types
  • #17162 feat(babel-types): Add support for BigInt literal conversion in valueToNode (@ishchhabra)

:bug: Bug Fix

• babel-helper-create-class-features-plugin, babel-plugin-transform-class-properties
  • #16816 fix: Class reference in type throws error (@liuxingbaoyu)
• babel-traverse
  • #17170 fix: Reset child scopes when scope.crawl() (@liuxingbaoyu)
• babel-helpers, babel-preset-typescript, babel-runtime-corejs2, babel-runtime-corejs3, babel-runtime
  • #17118 Fix: align behaviour to tsc rewriteRelativeImportExtensions (@JLHwung)
• babel-cli
  • #17182 fix: @babel/cli generates duplicate inline source maps (@liuxingbaoyu)
• babel-plugin-transform-named-capturing-groups-regex, babel-types
  • #17175 Generate computed proto key (@JLHwung)

:running_woman: Performance

• babel-types
  • #16870 perf: Improve builders of @babel/types (@liuxingbaoyu)
• babel-helper-create-regexp-features-plugin
  • #17176 fix: improve duplicate named groups check (@JLHwung)