unbuild
unbuild is a unified JavaScript build system for producing package builds.
What unbuild is
unbuild is a unified JavaScript build system for producing package builds. Its Rollup-based bundler supports TypeScript and can generate CommonJS and module formats together with type declarations. It can infer build configuration and entry points from package.json, or read settings from an unbuild key there or a supported build.config file. For bundleless distributions, its mkdist integration transpiles files individually. The --stub option uses jiti to create a dist stub, letting a project be linked during development without watching and rebuilding. unbuild integrates with untyped for type generation and checks for potentially missing or unused dependencies; it can fail CI when it finds build issues. CLI output reports output size and exports. The listed capabilities also include code splitting, tree shaking, source maps, and a plugin API. It is available free under the MIT license, with no free trial. The maintainers say they are experimenting with obuild as a next-generation successor based on rolldown.
Good
- Rollup-based bundler supports TypeScript
- Generates CommonJS, module formats, and type declarations
- Can infer configuration and entries from package.json
- Checks for potentially missing or unused dependencies
- Free under the MIT license
Watch out
- Maintainers are experimenting with obuild as a successor
- No free trial is listed
Who it suits
unbuild suits JavaScript and TypeScript developers building packages who want generated declarations, build checks, or bundleless output. It may also fit projects that need a stub-based development workflow or plugin API.
Verdict
unbuild combines package-building tasks with dependency checks and several output options. Its MIT-licensed free offering is worth considering if its Rollup-based workflow fits the project.
Plans and prices
From unbuild's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| MIT-licensed open-source software | Free | MIT license · No paid plans stated |
| unbuild | Free | MIT licensed · JavaScript build system |
The facts
Each one read from unbuild's own pages, with the date it was checked.
What it does
- Additional integration
- The README lists integration with untyped for type generation.checked 8 Oct 2026
- Build checks
- It checks for potential missing and unused dependencies and can fail CI when it finds build issues.checked 8 Oct 2026
- Bundleless builds
- Integration with mkdist enables bundleless distributions with file to file transpilation.checked 8 Oct 2026
- Bundling
- Its Rollup based bundler supports TypeScript and generates CommonJS and module formats plus type declarations.checked 8 Oct 2026
- Configuration
- It can infer build configuration and entries from package.json.checked 8 Oct 2026
- Configuration formats
- Configuration can be provided through an unbuild key in package.json or a build.config file with JavaScript, TypeScript, or JSON extensions listed in the README.checked 8 Oct 2026
- Configuration options
- Configuration can be provided through an unbuild key in package.json or a build.config file in supported JavaScript, TypeScript, or JSON extensions.checked 8 Oct 2026
- Development mode
- The --stub option creates a dist stub powered by jiti, so a project can be linked without watching and rebuilding during development.checked 8 Oct 2026
- Development workflow
- The --stub option creates a dist stub using jiti so a project can be linked without watching and rebuilding during development.checked 8 Oct 2026
- License
- The repository is released under the MIT license.checked 8 Oct 2026
- Output inspection
- CLI output includes output size and exports.checked 8 Oct 2026
- Purpose
- unbuild is a unified JavaScript build system.checked 8 Oct 2026
- Successor project
- The README says the maintainers are experimenting with obuild as a next generation successor based on rolldown.checked 8 Oct 2026
- Type generation
- unbuild integrates with untyped for type generation.checked 8 Oct 2026
The company
- Maker
- The repository is published under the unjs GitHub organization.checked 8 Oct 2026
