Common pitfalls and solutions

Learn from mistakes

Webpack errors are often configuration mistakes. Common issues: wrong loader order, missing file extensions, incorrect output paths, unused dependencies bundled. Use webpack-bundle-analyzer to visualize what's included. Read error messages carefully; Webpack provides helpful guidance. Test bundle output locally before deployment.

Debug bundle contents

Analyze what's in your bundles.

# Install analyzer
npm install --save-dev webpack-bundle-analyzer

# Add to webpack.config.js
const BundleAnalyzer = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
module.exports = {
  plugins: [new BundleAnalyzer()]
};

Output:

Opens http://localhost:8888 showing bundle composition visually

Test your output

Always test bundled output locally in development mode to catch issues early. Run the built app in a local server. Check browser console for errors. Verify your app works with minified code. Many issues only appear in production mode.

Quick check

Quick check: What's a common Webpack pitfall?

• Wrong loader order causing transformation failures.
• Using too many loaders.
• Minification is always bad.