Bundlephobia is a web service and API that measures the performance impact of npm packages on your application bundle.
The tool solves the problem of understanding how much code weight a dependency adds to your project before you install it. It works by building packages with webpack and reporting their minified and gzipped sizes, along with composition details. The service handles ES6 packages and supports CSS and SCSS packages in beta. It tracks historical size trends so you can monitor how a package's footprint changes over time.
Bundlephobia suits developers who want to make informed decisions about dependency choices during development. It works best for those evaluating npm packages before adding them to projects where bundle size matters. The tool provides both a web interface at bundlephobia.com and an API that powers integrations across package registries and development tools, including badges you can embed in documentation and extensions that display sizes directly on GitHub and npm pages.
The project actively seeks contributors and co-maintainers. Development involves handling edge cases around missing dependencies and build failures, with detailed error reporting available through browser developer tools to help diagnose issues with specific packages.
