Webpack is a module bundler. Its main purpose is to bundle JavaScript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging.

If you are building a modern JavaScript application, you have likely heard the term “webpack” mentioned before. Webpack is a static module bundler for JavaScript applications — it takes all the code from your application and makes it usable in a web browser. Modules are reusable chunks of code built from your app’s JavaScript, node_modules, images, and the CSS styles which are packaged to be easily used in your website. Webpack separates the code based on how it is used in your app, and with this modular breakdown of responsibilities, it becomes much easier to manage, debug, verify, and test your code.

When Webpack processes your application, it builds a dependency graph which maps out the modules that your project needs and generates one or more bundles. A bundle is a distinct grouping of connected code that has been compiled and transformed for the browser.

If one file depends on another (it uses the code from a separate file), Webpack treats this as a dependency. Webpack also takes your non-code assets (images, fonts, styles, etc.) and converts them to dependencies for your application.


At its core, webpack is a static module bundler for modern JavaScript applications. When webpack processes your application, it internally builds a dependency graph which maps every module your project needs and generates one or more bundles.

Since version 4.0.0, webpack does not require a configuration file to bundle your project. Nevertheless, it is incredibly configurable to better fit your needs.

To get started you only need to understand its Core Concepts:

  • Entry
  • Output
  • Loaders
  • Plugins
  • Mode
  • Browser Compatibility

This document is intended to give a high-level overview of these concepts, while providing links to detailed concept-specific use cases.

For a better understanding of the ideas behind module bundlers and how they work under the hood, consult these resources:

  • Manually Bundling an Application
  • Live Coding a Simple Module Bundler
  • Detailed Explanation of a Simple Module Bundler

official webpack.js.org

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