...If you're using dev-server through the Node.js API, the options in devServer will be ignored. Pass the options as a second parameter instead: new WebpackDevServer(compiler, {...}). Be aware that when exporting multiple configurations only the devServer options for the first configuration will be taken into account and used for all the configurations in the array. HTML template is required to serve the bundle, usually it is an index.html file. Make sure that script references are added into HTML, webpack-dev-server doesn't inject them automatically.