babel-loader

> I assume that if you integrate Babel and Webpack via webpack "loaders", some amount of work is saved (just guessing though) The Webpack babel-loader just calls Babel with the source code, it doesn't reuse Webpack's AST: https://github.com/babel/babel-loader/blob/master/src/index.... It has to do it that way, since Babel could parse some syntax that Webpack doesn't recognise (like Flow or TypeScript annotations). Webpack loaders can even take non-JS input and produce JS output (eg. "svgr" takes SVG images and produces React components) so I don't think Webpack can even assume that the input is JS at that point.

create-react-app is built on Webpack, for hot module replacement (HMR), and that requires a webpack loader. There's babel-loader and ts-loader. The stats in the projects are similar, but babel-loader is part of the babel project while ts-loader comes from an independent project, so it may be better integrated. Also ts-loader suggests using it with babel-loader. I'm not sure why, but if you install ts-loader and babel-loader you'll wind up with more dependencies than if you just install babel-loader. https://github.com/babel/babel-loader https://github.com/TypeStrong/ts-loader

Are you using the babel-loader[0] for webpack? That generates nice errors right in the webpack prompt. [0] https://github.com/babel/babel-loader