What is bundling?

Bundling is the process of taking many separate files-like JavaScript code, CSS styles, images, or other assets-and combining them into one (or a few) larger files. This makes it easier for a web browser or application to load everything it needs in fewer steps.

Let's break it down

Imagine you have a puzzle made of many tiny pieces. Each piece is a separate file. When you put all the pieces together into a single picture, you have one big piece that represents the whole puzzle. In bundling, a tool (called a bundler) reads each file, resolves any connections between them, and then writes the combined result into one or a few output files.

Why does it matter?

  • Faster loading: Fewer files mean fewer network requests, which speeds up page load times.
  • Better performance: Larger files can be compressed more efficiently, reducing overall size.
  • Simplified deployment: You only need to upload a handful of files to a server or CDN.
  • Dependency management: Bundlers automatically include the right versions of libraries your code relies on.

Where is it used?

  • Modern web applications built with frameworks like React, Angular, or Vue.
  • Single‑page applications (SPAs) that need all their code up front.
  • Mobile apps built with React Native or similar tools.
  • Desktop applications using Electron.
  • Any project that wants to ship JavaScript, CSS, or other assets efficiently.

Good things about it

  • Improves page speed and user experience.
  • Reduces the chance of missing files during deployment.
  • Allows use of modern JavaScript features while still supporting older browsers (through transpiling).
  • Enables code splitting, so only the needed parts are loaded initially.
  • Provides plugins for tasks like image optimization, linting, and environment variable injection.

Not-so-good things

  • Build step adds complexity; you need to configure and maintain the bundler.
  • Initial bundle can become large if not optimized, leading to slower first load.
  • Debugging can be harder because the code you see in the browser is transformed and combined.
  • Over‑reliance on bundling may hide performance issues that could be solved by better code organization.
  • Some developers prefer native ES modules in the browser to avoid a build step altogether.