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
// ES2015 arrow function
[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 babel#2168.
babeljs.io (the website)?
Want to report an issue withFor documentation and website issues please visit the babel/babel.github.io 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
Packages
The Babel repo is managed as a monorepo that is composed of many npm packages.
Core Packages
Package | Version | Dependencies |
---|---|---|
babel-core |
||
babylon |
||
babel-traverse |
||
babel-generator |
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
- These all use
babel-traverse
to traverse through the AST
- These all use
- 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
Package | Version | Dependencies |
---|---|---|
babel-cli |
||
babel-types |
||
babel-polyfill |
||
babel-runtime |
||
babel-register |
||
babel-template |
||
babel-helpers |
||
babel-code-frame |
babel-cli
is the CLI tool that runsbabel-core
and helps with outputting to a directory, a file, stdout and more (also includesbabel-node
). Check out the docs.babel-types
is used to validate, build and change AST nodes.babel-polyfill
is literally a wrapper aroundcore-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 withbabel-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.jsrequire
. 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 usingbabel-types
for building AST nodes.babel-helpers
is a set of pre-madebabel-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.
Presets
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
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
Babel | Daniel Tschinder | Logan Smyth | Henry Zhu |
![]() |
@danez | @loganfsmyth | @hzoo |
🐦 @babeljs | @TschinderDaniel | @loganfsmyth | @left_pad |
Members
Andrew Levine | Boopathi Rajaa | Brian Ng | Dan Harper | Diogo Franco | Aaron Ang | Artem Yavorsky |
@drewml | @boopathi | @existentialism | @danharper | @kovensky | @aaronang | @yavorsky |
@drewml | @heisenbugger | @existentialism | @DanHarper7 | @kovnsk | @_aaronang | @yavorsky_ |
Juriy Zaytsev | Kai Cataldo | Moti Zilberman | Sven Sauleau | Samuel Reed | Sergey Rubanov |
@kangax | @kaicataldo | @motiz88 | @xtuc | @STRML | @chicoxyzzy |
@kangax | @kai_cataldo | @motiz88 | @svensauleau | @STRML_ | @chicoxyzzy |
Non-Human Members
![]() |
---|
Babel Bot |
@babel-bot |
@babeljs |
Inactive members
Amjad Masad | James Kyle | Jesse McCarthy | Sebastian McKenzie |
@amasad | @thejameskyle | @jmm | @sebmck |
@amasad | @thejameskyle | @mccjm | @kittens |
Backers
Support us with a monthly donation and help us continue our activities. [Become a backer]
Sponsors
Become a sponsor and get your logo on our README on Github with a link to your site. [Become a sponsor]