Access local webpack dev servers from external devices

Sometimes we would like to access a local development server externally. It happens when we want to see how our web application works on mobile phones. Or co-workers want to see how it looks on their browsers.
The local server is available at http://localhost:PORT where PORT represents the port number that the server listens on. In order to make it accessible in the same network, we have to replace localhost with the IP address.
Webpack dev server allows the server to be available externally via the host option:
// webpack.config.js
module.exports = {
devServer: {
host: '',
port: 8001,
The host option can be passed to the command line interface as well:
webpack serve --host
With the configurations above, we can access the server internally (http://localhost:8001) and externally (http://THE-IP-ADDRESS:8001).