bundle-stats

Demos: Bundle analysis comparison · Bundle analysis

BundleStats

Analyze bundle stats(bundle size, assets, modules, packages) and compare the results between different builds. Support for webpack, rspack, vite, rollup and rolldown.

- Bundle size and totals by file type(css, js, img, etc)
- Insights: duplicate packages, new packages
- Initial JS/CSS, Cache invalidation, and other bundle metrics
- Assets report (entrypoint, initial, types, changed, delta)
- Modules report (changed, delta, chunks, duplicate count and percentage)
- Packages report (count, duplicate, changed, delta)
:star: Side by side comparison for multiple builds

Table of Contents

• Install as global dependency
• Install as dev dependency
• Webpack configuration
• Usage
• Compare mode
• Framework specific plugins
• Related projects

Install as global dependency

npm install -g bundle-stats

or

yarn global add bundle-stats

Install as dev dependency

npm install --dev bundle-stats

or

yarn add --dev bundle-stats

Output webpack stats

The CLI is consuming the Webpack stats JSON file. The following webpack stats options are needed:

{
  stats: {
    // required
    assets: true,
    chunks: true,
    modules: true,
    // optional
    builtAt: true,
    hash: true
  }
}

How to configure webpack for better debugging and monitoring

You can output the webpack stats JSON file using webpack-cli --json option:

npx webpack --mode production --json artifacts/webpack-stats.json

• How to output webpack stats JSON file using webpack-cli
• How to output webpack stats JSON file using webpack-stats-plugin

Usage

$ bundle-stats -h
Usage: bundle-stats OPTIONS [WEBPACK_STATS_FILE]...

Options:
      --demo               Generate demo reports      [boolean] [default: false]
      --compare            Use local saved stats for comparison
                                                       [boolean] [default: true]
      --baseline           Save current stats as baseline
                                                      [boolean] [default: false]
      --baseline-filepath  Baseline filepath, default:
                           node_modules/.cache/bundle-stats/baseline.json
                                                                        [string]
      --html               Save HTML report            [boolean] [default: true]
      --json               Save JSON data             [boolean] [default: false]
  -d, --out-dir            Output directory                             [string]
  -h, --help               Show help                                   [boolean]
  -v, --version            Show version number                         [boolean]

$ bundle-stats --html --json __fixtures__/webpack-stats-0.json __fixtures__/webpack-stats-1.json
  ✔ Read Webpack stat files
  ✔ Read baseline data
  ↓ Write baseline data [skipped]
    → Not a baseline job (see --baseline).
  ✔ Gather data
  ✔ Generate reports
  ✔ Save reports

┌─────────────────────────────────────────────────┐
│                                                 │
│   Bundle size decreased with 3.06KB (-0.38%).   │
│                                                 │
└─────────────────────────────────────────────────┘

Artifacts saved:
- ./dist/bundle-stats.html
- ./dist/bundle-stats.json

Compare mode

In compare mode, the metrics are compared against an existing(node_modules/.cache/bundle-stats/baseline.json) Webpack stats file(baseline). To generate the baseline webpack stats, use --baseline option:

# Checkout to the branch/tag/commit where you want to generate the baseline
$ git checkout master

# Build your application
$ npm run build

# Run bundle-stats with --baseline option. This will save the baseline data on node_modules/.cache/bundle-stats/baseline.json
$ bundle-stats --baseline artifacts/webpack-stats.json
 ✔ Read Webpack stat files
 ↓ Read baseline data [skipped]
   → Missing baseline stats, see "--baseline" option.
 ✔ Write baseline data
 ✔ Process data
 ✔ Generate reports
 ✔ Save reports

┌─────────────────────────────────────────────────┐
│                                                 │
│   Bundle size decreased with 3.06KB (-0.38%).   │
│                                                 │
└─────────────────────────────────────────────────┘

Artifacts saved:
- ./dist/bundle-stats.html

# Checkout to the working branch/tag/commit
$ git checkout MY_FEATURE_BRANCH

# Build your application
$ npm run build

# Run bundle-stats - the report is going to compare the current data against the generated baseline
$ bundle-stats artifacts/webpack-stats.json
 ✔ Read Webpack stat files
 ✔ Read baseline data
 ↓ Write baseline data [skipped]
   → Not a baseline job (see --baseline).
 ✔ Process data
 ✔ Generate reports
 ✔ Save reports

┌─────────────────────────────────────────────────┐
│                                                 │
│   Bundle size decreased with 3.06KB (-0.38%).   │
│                                                 │
└─────────────────────────────────────────────────┘

Artifacts saved:
- ./dist/bundle-stats.html

The option can be disabled using --no-compare option.

Framework specific plugins

• Webpack
• Gatsby
• Next

Related projects

:cyclone: relative-ci.com

Optimize your web app's performance with automated bundle stats analysis and monitoring.

• :crystal_ball: In-depth bundle stats analysis for every build
• :chart_with_upwards_trend: Monitor bundle stats changes and identify opportunities for optimizations
• :bell: Rule based automated review flow, or get notified via GitHub Pull Request comments, GitHub check reports and Slack messages
• :wrench: Support for webpack and beta support for Vite/Rollup
• :hammer: Support for all major CI services(CircleCI, GitHub Actions, Gitlab CI, Jenkins, Travis CI)
• :nut_and_bolt: Support for npm, yarn and pnpm; support for monorepos
• :two_hearts: Always free for Open Source

:rocket: Get started

:first_quarter_moon: relative-ci/compare

Standalone web application to compare Webpack/Lighthouse/Browsertime stats.

Compare bundle stats

:zap: bundle-stats-action

Github Action that generates bundle-stats reports.

Other packages

bundle-stats-webpack-plugin

Webpack plugin to generate bundle stats report for webpack/rspack.

gatsby-plugin-bundle-stats

Gatsby plugin for bundle-stats.

next-plugin-bundle-stats

Next.js plugin for bundle-stats.

rollup-plugin-bundle-stats

Rollup plugin to generate bundle stats report for vite/rolldown/rollup.