Microbundle is a zero-configuration bundler for tiny modules powered by Rollup.
The tool solves the problem of bundling small JavaScript libraries without requiring complex build configuration. It works by reading your package.json to determine entry points and automatically generating optimized output in multiple formats. The bundler handles transpilation through Babel with support for modern JavaScript features like async/await, produces compressed output using Terser, and tracks gzipped bundle sizes automatically. It requires only a single dependency and generates CommonJS, UMD, and ECMAScript module formats from each entry point.
Microbundle suits developers building small utility libraries and modules who want to avoid build configuration overhead. It works well for projects that need to support multiple module formats and browser environments without manual setup. The tool is particularly valuable when you want to ship modern JavaScript syntax to modern browsers while maintaining compatibility with older environments through its Modern Mode output, which preserves features like async/await and arrow functions for browsers supporting ES modules while remaining significantly smaller than fully transpiled alternatives.
The project maintains active engagement with its codebase, regularly addressing issues and pull requests from the community. Development shows consistent attention to keeping dependencies current and responding to user feedback about bundling behavior and output optimization.
