Quoting babel docs https://babeljs.io/docs/en/babel-standalone#usage : “If you want to use your browser’s native support for ES Modules, you’d normally need to set a type=”module” attribute on your script tag. With @babel/standalone, set a data-type=”module” attribute instead” For some reason though, when including my main index.js file (which imports other js / jsx files using import), it seems like babel is