Next.js + Webpack Bundle Analyzer

Use webpack-bundle-analyzer in your Next.js project

Installation

npm install @next/bundle-analyzer

or

yarn add @next/bundle-analyzer

Note: if installing as a devDependency make sure to wrap the require in a process.env check as next.config.js is loaded during next start as well.

Usage with environment variables

Create a next.config.js (and make sure you have next-bundle-analyzer set up)

const withBundleAnalyzer = require('@next/bundle-analyzer')({
  enabled: process.env.ANALYZE === 'true',
})
module.exports = withBundleAnalyzer({})

Or configuration as a function:

module.exports = (phase, defaultConfig) => {
  return withBundleAnalyzer(defaultConfig)
}

Then you can run the command below:

# Analyze is done on build when env var is set
ANALYZE=true yarn build

When enabled three HTML files (client.html, edge.html and nodejs.html) will be outputted to <distDir>/analyze/. One will be for the nodejs server bundle, one for the edge server bundle, and one for the browser bundle.

Options

To disable automatically opening the report in your default browser, set openAnalyzer to false:

const withBundleAnalyzer = require('@next/bundle-analyzer')({
  enabled: process.env.ANALYZE === 'true',
  openAnalyzer: false,
})
module.exports = withBundleAnalyzer({})

Usage with next-compose-plugins

From version 2.0.0 of next-compose-plugins you need to call bundle-analyzer in this way to work

const withPlugins = require('next-compose-plugins')
const withBundleAnalyzer = require('@next/bundle-analyzer')({
  enabled: process.env.ANALYZE === 'true',
})

module.exports = withPlugins([
  [withBundleAnalyzer],
  // your other plugins here
])