Browserify vs rollup: What are the differences?

Introduction

In web development, JavaScript bundlers are essential for organizing and optimizing code. Two popular bundlers are Browserify and Rollup. While they serve a similar purpose, there are some key differences between the two.

1. Module Resolution: Browserify primarily relies on the CommonJS module system, which is prevalent in Node.js applications. It uses the require() function to import and export modules. On the other hand, Rollup adopts the ES module system, leveraging the import and export statements. This system offers better tree-shaking capabilities, resulting in smaller bundle sizes.

2. Tree Shaking: Rollup excels in tree shaking, which is the process of eliminating unused code from the final bundle. It can recognize dead code and remove it, resulting in smaller and more optimized bundles. Browserify, on the other hand, lacks built-in tree-shaking capabilities and may include unused code in the bundle.

3. Code Splitting: Rollup provides built-in code splitting capabilities, allowing developers to split their code into smaller chunks that can be loaded on-demand. This feature is particularly useful for large applications with many modules. Browserify lacks native support for code splitting, which can result in larger initial bundle sizes.

4. Configuration: Browserify utilizes a single configuration file, typically named package.json or browserify.js, to specify settings and options. In contrast, Rollup uses a dedicated configuration file, usually named rollup.config.js, where developers can define various options such as input and output files, plugins, and external dependencies.

5. Plugin Ecosystem: While both bundlers offer a wide range of plugins to extend functionality, the plugin ecosystem for Rollup is more extensive. Rollup's ecosystem includes various plugins for tasks like transpiling code, generating sourcemaps, and optimizing output. Browserify also has a significant number of plugins available, but the variety and community support might be slightly more limited.

6. Customization and Extensibility: Rollup provides a more flexible and extensible architecture, allowing developers to customize and extend its functionality to suit their specific needs. It offers a modular plugin system, making it easier to create and integrate custom plugins. Browserify, while still customizable, has a more opinionated approach and may require more workarounds for specific requirements.

In summary, Browserify and Rollup differ in their module resolution systems, tree-shaking capabilities, code splitting support, configuration approaches, plugin ecosystems, and customization options. While both bundlers serve the purpose of bundling JavaScript code, Rollup offers superior tree-shaking and code splitting features, while Browserify might be better suited for CommonJS-centric applications.