Total extension bundle size optimized and remains under 5MB

Extension bundle size directly affects install time, update time, and popup load time on every user's machine. A bloated bundle — caused by unminified libraries, uncompressed images, or unnecessary dependencies like full lodash or moment.js — forces users to download and parse megabytes of JavaScript the extension doesn't need. ISO 25010:2011 performance-efficiency.resource-utilisation identifies this as a defect. Chrome Web Store rejects extensions over 128MB, but the practical ceiling for perceived performance is far lower; extensions over 5MB noticeably slow popup initialization on mid-range hardware.

Enable production mode in your bundler to activate minification and tree-shaking, then audit the largest files and replace heavyweight dependencies with lighter alternatives.

// webpack.config.js
module.exports = {
  mode: 'production',       // Enables minification and tree-shaking
  optimization: { minimize: true },
  devtool: false,           // Exclude source maps from production build
};

Replace moment.js with date-fns, import lodash functions individually (import debounce from 'lodash/debounce'), and compress images with imagemin or squoosh before bundling. Run du -sh dist/* sorted by size to identify the largest offenders.