webpack is a bundler for modules. The main purpose is to bundle javascript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging just about any resource or asset.
TL;DR
- Bundles both CommonJs and AMD modules (even combined).
- Can create a single bundle or multiple chunks that are asynchronously loaded at runtime (to reduce initial loading time).
- Dependencies are resolved during compilation reducing the runtime size.
- Loaders can preprocess files while compiling, e.g. coffeescript to javascript, handlebars strings to compiled functions, images to Base64, etc.
- Highly modular plugin system to do whatever else your application requires.
Check out webpack's documentation for quick Getting Started guide, in-depth usage, tutorials and resources.
project:
npm install webpack --save-dev
global:
npm install webpack -g
Usage
http://webpack.github.io/docs/tutorials/getting-started/
Take a look at the examples folder.
webpack has a rich plugin interface. Most of the features within webpack itself use this plugin interface. This makes webpack very flexible.
webpack uses async I/O and has multiple caching levels. This makes webpack fast and incredibly fast on incremental compilations.
webpack enables use of loaders to preprocess files. This allows you to bundle any static resource way beyond javascript. You can easily write your own loaders using node.js.
Loaders are activated by using loadername! prefixes in require() statements,
or are automatically applied via regex from your webpack configuration.
Please see Using Loaders for more information.
basic
json: Loads file as JSONraw: Loads raw content of a file (as utf-8)val: Executes code as module and consider exports as JavaScript codescript: Executes a JavaScript file once in global context (like in script tag), requires are not parsed.
packaging
file: Emits the file into the output folder and returns the (relative) url.url: The url loader works like the file loader, but can return a Data Url if the file is smaller than a limit.image: Compresses your images. Ideal to use together withfileorurl.svgo-loader: Compresses SVG images using svgo librarybaggage: Automatically require any resources related to the required onepolymer-loader: Process HTML & CSS with preprocessor of choice andrequire()Web Components like first-class modules.
dialects
coffee: Loads coffee-script like JavaScriptbabel: Turn ES6 code into vanilla ES5 using Babel.livescript: Loads LiveScript like JavaScriptsweetjs: Use sweetjs macros.traceur: Use future JavaScript features with Traceur.typescript: Loads TypeScript like JavaScript.
templating
html: Exports HTML as string, require references to static resources.jade: Loads jade template and returns a functionhandlebars: Loads handlebars template and returns a functionractive: Pre-compiles Ractive templates for interactive DOM manipulationmarkdown: Compiles Markdown to HTMLng-cache: Puts HTML partials in the Angular's $templateCache
styling
style: Add exports of a module as style to DOMcss: Loads css file with resolved imports and returns css codeless: Loads and compiles a less filesass: Loads and compiles a scss filestylus: Loads and compiles a stylus file
misc
po: Loads a PO gettext file and returns JSONmocha: Do tests with mocha in browser or node.jseslint: PreLoader for linting code using ESLint.jshint: PreLoader for linting code.jscs: PreLoader for style checking.injectable: Allow to inject dependencies into modulestransform: Use browserify transforms as loader.
For the full list of loaders, see list of loaders.
webpack supports both AMD and CommonJS module styles. It performs clever static analysis on the AST of your code. It even has an evaluation engine to evaluate simple expressions. This allows you to support most existing libraries out of the box.
webpack allows you to split your codebase into multiple chunks. Chunks are loaded asynchronously at runtime. This reduces the initial loading time.
webpack can do many optimizations to reduce the output size of your javascript by deduplicating frequently used modules, minifying, and giving you full control of what is loaded initially and what is loaded at runtime through code splitting. It can also can make your code chunks cache friendly by using hashes.
// webpack is a module bundler
// This means webpack takes modules with dependencies
// and emits static assets representing those modules.
// dependencies can be written in CommonJs
var commonjs = require("./commonjs");
// or in AMD
define(["amd-module", "../file"], function(amdModule, file) {
// while previous constructs are sync
// this is async
require(["big-module/big/file"], function(big) {
// for async dependencies webpack splits
// your application into multiple "chunks".
// This part of your application is
// loaded on demand (Code Splitting)
var stuff = require("../my/stuff");
// "../my/stuff" is also loaded on demand
// because it's in the callback function
// of the AMD require
});
});
require("coffee!./cup.coffee");
// "Loaders" can be used to preprocess files.
// They can be prefixed in the require call
// or configured in the configuration.
require("./cup");
// This does the same when you add ".coffee" to the extensions
// and configure the "coffee" loader for /\.coffee$/
function loadTemplate(name) {
return require("./templates/" + name + ".jade");
// many expressions are supported in require calls
// a clever parser extracts information and concludes
// that everything in "./templates" that matches
// /\.jade$/ should be included in the bundle, as it
// can be required.
}
// ... and you can combine everything
function loadTemplateAsync(name, callback) {
require(["bundle?lazy!./templates/" + name + ".jade"],
function(templateBundle) {
templateBundle(callback);
});
}You can run the node tests with npm test. 
You can run the browser tests:
cd test/browsertests
node build
and open tests.html in browser.
Most of the time, if webpack is not working correctly for you it is a simple configuration issue.
If you are still having difficulty after looking over your configuration carefully, please post a question to StackOverflow with the webpack tag. Questions that include your webpack.config.js and relevant files are more likely to receive responses.
If you have discovered a bug or have a feature suggestion, feel free to create an issue on Github.
If you create a lodaer or plugin, please consider open sourcing it, putting it
on NPM and following the x-loader, x-plugin convention.
You are also welcome to correct any spelling mistakes or any language issues.
If you want to discuss something or just need help, here is our gitter.im room.
Copyright (c) 2012-2015 Tobias Koppers
MIT (http://www.opensource.org/licenses/mit-license.php)
This is a freetime project. My time investment fluctuates randomly. If you use webpack for a serious task you may want me to invest more time. Or if you make some good revenue you can give some money back. Keep in mind that this project may increase your income. It makes development and applications faster and reduces the required bandwidth.
I'm very thankful for every dollar. If you leave your username or email I may show my thanks by giving you extra support.
