Webpack reads your code and finds all module dependencies, for each module. It stores this info in a single tree. This means you can optimize your dependencies. Or analyze entire tree after bundling: https://webpack.github.io/analyse/ After version 2.0.0, it will be possible to eliminate dead export code: http://www.2ality.com/2015/12/webpack-tree-shaking.html Also, it has other killer features like dev server, hot code push and other... In shorten, Webpack is better.