The compiler for writing next generation JavaScript.
Babel is a community-driven tool that helps you write code in the latest version of JavaScript.
When your supported environments don't support certain features natively, Babel will help you compile those features down to a supported version.
In
[1, 2, 3].map((n) => n + 1);
Out
[1, 2, 3].map(function(n) {
return n + 1;
});
Try it out at our REPL and follow us at @babeljs.
FAQ
Docs?
Check out our website: babeljs.io
Looking for support?
For questions and support please visit our discussion forum, sign up for our Slack community, or StackOverflow.
Want to report a bug or request a feature?
Bugs and feature requests can be posted at https://github.com/babel/babel/issues.
We've moved our issues from phabricator back to github issues!
Former phabricator issue URLs now automatically redirect to their corresponding Github issue:
https://phabricator.babeljs.io/T2168 mostly corresponds to https://github.com/babel/babel/issues/2168.
Want to report an issue with babeljs.io (the website)?
For documentation and website issues please visit the babel/website repo.
Want to contribute to Babel?
Check out our CONTRIBUTING.md. If you have already joined Slack, join our #development channel!
You can also start by checking out the issues with the help-wanted label.
Our discussions/notes/roadmap: babel/notes
Our progress on TC39 proposals: babel/proposals
Packages
The Babel repo is managed as a monorepo that is composed of many npm packages.
Core Packages
babel-core
is the Babel compiler itself; it exposes the babel.transform
method, where transformedCode = transform(src).code
.
The compiler can be broken down into 3 parts:
- The parser:
babylon
(moved to a separate repo and versioned independently) - The transformer[s]: All the plugins/presets
- The generator:
babel-generator
The flow goes like this:
input string -> babylon
parser -> AST
-> transformer[s] -> AST
-> babel-generator
-> output string
Check out the babel-handbook
for more information on this.
Other
babel-cli
is the CLI tool that runs babel-core
and helps with outputting to a directory, a file, stdout and more (also includes babel-node
). Check out the docs.babel-types
is used to validate, build and change AST nodes.babel-polyfill
is literally a wrapper around core-js
and regenerator-runtime. Check out the docs.babel-runtime
is similar to the polyfill except that it doesn't modify the global scope and is to be used with babel-plugin-transform-runtime
(usually in library/plugin code). Check out the docs.babel-register
is a way to automatically compile files with Babel on the fly by binding to Node.js require
. Check out the docs.babel-template
is a helper function that allows constructing AST nodes from a string presentation of the code; this eliminates the tedium of using babel-types
for building AST nodes.babel-helpers
is a set of pre-made babel-template
functions that are used in some Babel plugins.babel-code-frame
is a standalone package used to generate errors that print the source code and point to error locations.
After Babel 6, the default transforms were removed; if you don't specify any plugins/presets, Babel will just return the original source code.
The transformer[s] used in Babel are the independent pieces of code that transform specific things. For example: the es2015-arrow-functions
transform specifically changes arrow functions into regular functions. A preset is simply an array of plugins that make it easier to run a whole a set of transforms without specifying each one manually.
Package | Version | Dependencies | Description |
---|
babel-preset-env | | | automatically determines plugins and polyfills you need based on your supported environments |
You can find community maintained presets on npm
Plugins are the heart of Babel and what make it work.
You can find community plugins on npm.
Transform Plugins
There are many kinds of plugins: ones that convert ES6/ES2015 to ES5, transform to ES3, minification, JSX, flow, experimental features, and more. Check out our website for more.
Syntax Plugins
These just enable the transform plugins to be able to parse certain features (the transform plugins already include the syntax plugins so you don't need both): babel-plugin-syntax-x
. Check out our website for more.
Helpers
These are mostly for internal use in various plugins: babel-helper-x
.
Team
Core members
Members
Non-Human Members
Inactive members
Backers
Support us with a monthly donation and help us continue our activities. [Become a backer]
Become a sponsor and get your logo on our README on Github with a link to your site. [Become a sponsor]
License
MIT