Babel (transcompiler)

Babel
	Logo
Original author(s)	Sebastian McKenzie
Developer(s)	Contributors
Initial release	September 28, 2014; 10 years ago
Stable release	7.27.0 / 24 March 2025; 45 days ago
Repository	github.com/babel/babel ;
Written in	JavaScript
Operating system	Linux, macOS, Solaris, FreeBSD, OpenBSD, AIX, Microsoft Windows
Type	Compiler
License	MIT
Website	babeljs.io

Babel is a free and open-source JavaScript transcompiler that is mainly used to convert ECMAScript 2015+ (ES6+) code into backwards-compatible JavaScript code that can be run by older JavaScript engines. It allows web developers to take advantage of the newest features of the language.^[4]

Developers can use new JavaScript language features by using Babel to convert their source code into versions of JavaScript that a Web browser can process.^[5] Babel can also be used to compile TypeScript into JavaScript.^[6] The core version of Babel was downloaded 5 million times a month in 2016, and this increased to 16 million times a week in 2019.^[7]^[8]

Babel plugins transform syntax that is not widely supported into a backward-compatible version. For example, arrow functions, which are specified in ES6, are converted into regular function declarations.^[9] Non-standard JavaScript syntax such as JSX can also be transformed.^[10]^[11]

Babel can automatically inject polyfills provided by core-js^[12] for support features that are missing entirely from JavaScript environments. For example, static methods such as Array.from and built-ins such as Promise are available only in ES6 and above, but they can be used in older environments if core-js is used.