Webpack and Rollup bundle size comparison without and with barrel files

Webpack

With barrels: 5 modules, 4.39 kB Without barrels: 3 modules, 3.56 kB

Rollup

With barrels: 448 bytes Without barrels: 334 bytes

Note on size:

the generated output is smaller in both cases
webpack has a small overhead independent of the size of the application.
in general rollup generates a more compact output

Folder structure

src/with-barrels: example code using barrel files
src/without-barrels: example code without barrel files
output: generated bundles
rollup-with-barrels.config: rollup config for barrels example
rollup-without-barrels.config: rollup config for without barrels example
webpack.config.js: webpack config for both examples

Generate bundles

npm i
npm run build