next.js/examples/with-webpack-bundle-analyzer/next.config.js

const {BundleAnalyzerPlugin} = require('webpack-bundle-analyzer')
module.exports = {
  webpack: (config, { dev }) => {
    // Perform customizations to config
    config.plugins.push(
      new BundleAnalyzerPlugin({
        // For all options see https://github.com/th0r/webpack-bundle-analyzer#as-plugin
        analyzerMode: 'server',
        analyzerHost: '127.0.0.1',
        analyzerPort: 8888,
        openAnalyzer: false
      })
    )
    // Important: return the modified config
    return config
  }
}