# developit/microbundle

📦 Zero-configuration bundler for tiny modules.

Repository: https://github.com/developit/microbundle
Canonical: https://ross.abutalabs.com/products/microbundle
Homepage: https://npm.im/microbundle
Language: JavaScript
License: MIT
License Family: permissive
Topics: bundle, module-bundler, build, microlib, rollup, tiny-modules, umd
Last push: 2026-02-01T19:24:38+00:00

## Health v2 (maintenance only)
Score: 52/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 65, release rhythm 8, longevity 100
- inputs: {"age_days": 3187, "days_push": 213, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 8129, forks 359 (observed 2026-08-28T04:10:13.799214+00:00)

## What it is
Microbundle is a zero-configuration JavaScript module bundler for small libraries, built on top of Rollup. It bundles a library into CJS, ESM, and UMD output formats from a single dependency, with built-in TypeScript support, Terser minification, and watch mode.

## Use cases
- bundle a small javascript library for npm
- build a library with zero configuration
- generate cjs, esm and umd bundles from one source
- bundle a typescript library without config
- track gzipped bundle size of my npm package
- watch mode rebuilds for library development

## When to choose
- you are publishing a small-to-medium JS/TS library to npm and want minimal setup
- you need multiple module output formats (CJS, ESM, UMD) from one command
- you prefer convention-over-configuration with just a package.json

## When to avoid
- you are bundling a large application with complex code-splitting needs
- you need heavy custom build pipelines or many plugins
- you want full control over the bundler configuration

## Facets
- artifact type: cli-tool
- maturity: active
- function: build-tool, cli, developer-tools
- domain: developer-tools, web-development, frontend
- platform: cli, cross-platform
- tags: module-bundler, rollup, zero-configuration, javascript, typescript, npm, umd, esm, cjs, micro-libraries, nodejs

## Member repositories
- developit/microbundle (main) score 52

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:13.799214+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:21:11.029017+00:00, confidence not recorded.
  - readme: https://github.com/developit/microbundle (fetched 2026-08-28T04:10:13.799214+00:00, sha 88c115db1aa2)
  - registry_npm: https://registry.npmjs.org/microbundle (fetched 2026-08-29T08:28:51.510769+00:00, sha f064cb719397)
- Data as of 2026-08-30T08:39:29.467469+00:00.