@babel/runtime

What is @babel/runtime?

The @babel/runtime package is a library that includes Babel modular runtime helpers and a version of regenerator-runtime. It is used to avoid polluting the global scope and to reduce the size of the compiled output by deduplicating helper functions that are commonly used by Babel-transpiled code. It is particularly useful when building libraries or applications that need to be optimized for size and scope isolation.

What are @babel/runtime's main functionalities?

Modularized Helpers

This feature allows you to use Babel's helper functions in a modular way, without including them in every file that needs them, thus reducing redundancy and file size.

import _classCallCheck from '@babel/runtime/helpers/classCallCheck';

class MyClass {
  constructor() {
    _classCallCheck(this, MyClass);
    // class body
  }
}

Regenerator Runtime

Includes a version of the regenerator runtime to enable the use of async/await and generator functions in environments that do not natively support them.

import 'regenerator-runtime/runtime';

async function asyncCall() {
  await someAsyncFunction();
}

Other packages similar to @babel/runtime

core-js

Similar to @babel/runtime, core-js is a modular standard library for JavaScript, which includes polyfills for ECMAScript features. It is often used in conjunction with Babel to ensure that newer language features will work in older environments. It is more comprehensive than @babel/runtime but can lead to larger bundle sizes if not used carefully.

tslib

tslib is a runtime library for TypeScript that includes helper functions similar to those in @babel/runtime. It is used to support features from TypeScript such as async/await, spread operators, and others without duplicating code. It is specific to TypeScript, whereas @babel/runtime is used with Babel and can be used with JavaScript or TypeScript.

README

@babel/runtime

babel's modular runtime helpers

See our website @babel/runtime for more information.

Install

Using npm:

npm install --save @babel/runtime

or using yarn:

yarn add @babel/runtime

Changelog

v7.26.7 (2025-01-24)

:bug: Bug Fix

• babel-helpers, babel-preset-env, babel-runtime-corejs3
  • #17086 Make "object without properties" helpers ES6-compatible (@tquetano-netflix)
• babel-plugin-transform-typeof-symbol
  • #17085 fix: Correctly handle typeof in arrow functions (@liuxingbaoyu)
• babel-parser
  • #17079 Respect ranges option in estree method value (@JLHwung)
• babel-core
  • #17052 Do not try to parse .ts configs as JSON if natively supported (@nicolo-ribaudo)
• babel-plugin-transform-typescript
  • #17050 fix: correctly resolve references to non-constant enum members (@branchseer)
• babel-plugin-transform-typescript, babel-traverse, babel-types
  • #17025 fix: Remove type-only import x = y.z (@liuxingbaoyu)