Recently Babel 6 was released. One of the main changes in it was performance optimisations. So updating makes big sense. It appeared to be very easy. I use Webpack + Babel for JS files and here is a quick manual for updating: How to update (in short)package.json (npm modules dependencies)Babel 5: “babel”: “^5.0.0”, “babel-core”: “^5.0.0”, “babel-loader”: “^5.0.0”Babel 6: "babel-core": "^6.0.0", "b