PACKAGE · BUNDLER

rollup

Next-generation ES module bundler

WEEKLY DOWNLOADS 60.6M
STARS 26.3K
FORKS 1.7K
OPEN ISSUES 607
GZIP SIZE 170.8 kB
UNPACKED SIZE 2.8 MB
DEPENDENCIES 2
LAST UPDATED 3mo ago
DOWNLOAD TRENDS

rollup downloads — last 12 months

Download trends for rollup1 download series from Jun 2025 to May 2026. Use left and right arrow keys to inspect monthly values.0117.7M235.4M353.2M470.9MJun 2025SepDecMarMay 2026
rollup
ABOUT ROLLUP

Rollup is a modern JavaScript module bundler designed to efficiently package JavaScript code for the web and Node.js environments. It addresses the challenge of managing dependencies and optimizing code output, especially as applications grow in complexity and scale. By focusing on ES Modules (ESM) as its native format, Rollup excels at producing cleaner, smaller bundles compared to older bundlers that rely on CommonJS.

Its core philosophy centers on producing highly optimized and, often, smaller bundles by leveraging the static analysis capabilities of ES Modules. This allows Rollup to perform tree-shaking effectively, removing unused code and significantly reducing the final output size. Rollup is primarily aimed at developers building libraries and modern web applications who value code efficiency and maintainability.

Rollup's API revolves around a plugin system, enabling extensive customization. Key patterns include the use of Rollup Plugins to transform code (e.g., Babel for transpilation, PostCSS for styling) and to integrate with various workflows. The core `rollup.rollup` function and the `rollup.watch` API are central to building and observing code changes, respectively, facilitating development and production builds.

It integrates seamlessly into modern development tooling. Rollup configurations are often managed via a `rollup.config.js` file, which can be easily adopted by build systems like Vite or integrated into custom scripts. Its focus on ES Modules makes it a natural fit for frameworks and libraries that adopt ESM standards, simplifying dependency management across different parts of a project.

With 116.8 million weekly downloads, Rollup demonstrates significant adoption and maturity. Its output is known for its efficiency, contributing to faster load times for web applications and efficient module loading in Node.js. The unpacked size of 2.8 MB and a gzipped bundle size of 170.8 kB indicate a relatively lean footprint for the bundler itself, while its primary goal is to create even leaner application bundles.

While powerful, Rollup's explicit focus on ES Modules can sometimes require additional configuration for projects heavily reliant on older module formats, though plugins often mitigate this. Developers should be aware that extensive plugin configurations can sometimes add complexity to the build process. Its open issue count of 607 suggests an active development community addressing ongoing improvements and user-reported concerns.

WHEN TO USE
  • When publishing JavaScript libraries that need to support multiple module formats (ESM, CJS) with minimal dead code.
  • When building modern web applications that benefit from efficient tree-shaking of ES Module dependencies.
  • When integrating with frameworks that leverage ES Module static analysis for optimized builds, such as certain configurations of SvelteKit or Vue.
  • When you need a highly configurable build process through a robust plugin API to handle transformations like TypeScript compilation or CSS preprocessing.
  • When targeting environments that strictly adhere to ES Module specifications for optimal runtime performance.
  • When optimizing application bundles for reduced download size and faster initial load times by eliminating unused code.
WHEN NOT TO USE
  • If your project primarily consists of legacy CommonJS modules and requires minimal transformation, a simpler bundler might suffice.
  • For single-page applications where initial setup simplicity is paramount and advanced build optimizations are less critical, a framework-integrated CLI tool may offer a quicker start.
  • If your primary need is quick iteration during development without extensive code splitting or complex asset management, a development server without explicit bundling might be faster.
  • When dealing with very small, self-contained scripts that do not have external dependencies and do not require optimization, manual scripting or basic concatenation can be adequate.
  • If you require a bundler with built-in, opinionated support for specific frameworks that is more integrated than what Rollup's plugin model provides.

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COMPARISONS 5
rollup vs webpack ★ 65.8K · 23.2M/wk rollup vs vite ★ 81.1K · 67.5M/wk rollup vs parcel ★ 44.0K · 191.8K/wk rollup vs @rspack/core ★ 12.7K · 2.9M/wk rollup vs esbuild ★ 39.9K · 120.2M/wk