This example shows how to implement runtime code branching for universal apps. We have a very simple javascript file that outputs a different message in the console whether you are running it in Node.js or in the browser. Before running the examples you need to install the dependencies with: npm install Then you need to generate the bundle file for the browser with: node_modules/.bin/webpack Finally you can run the script on the browser by just opening main.html and looking at the debug console, or run the script in Node.js with: node src/main.js