To maintain fast load times when building an Angular app, especially for production, it's essential to optimize how your app is bundled, served, and initialized. Here's a guide with practical tips:
1. Use Angular's Production Build
Always build with the production flag:
ng build --configuration production
This enables:
- AOT (Ahead-of-Time Compilation)
- Minification & Uglification
- Tree-shaking (removes unused code)
2. Lazy Load Feature Modules
Split large modules into lazy-loaded ones:
const routes: Routes = [
{ path: 'admin', loadChildren: () => import('./admin/admin.module').then(m => m.AdminModule) }
];
Loads modules only when needed, reducing initial bundle size.
3. Use OnPush Change Detection
Set components to ChangeDetectionStrategy.OnPush to reduce re-renders and improve performance:
@Component({
changeDetection: ChangeDetectionStrategy.OnPush
})
4. Optimize Third-party Libraries
- Import only what you need (e.g.,
import { debounceTime } from 'rxjs/operators').
- Avoid heavy UI libraries unless necessary.
- Remove unused polyfills or legacy support if not required.
5. Enable Gzip or Brotli Compression on Server
Serve your built files with compression (Nginx, Node.js, Firebase Hosting, etc.).
This drastically reduces file sizes over the wire.
6. Preload & Cache Static Assets
Use Angular Service Workers (PWA support) or browser cache strategies to cache:
- JS bundles
- Fonts & images
- CSS files
7. Monitor Performance
Use:
npx source-map-explorer dist/*.js
- Chrome DevTools → Network tab → check initial load size and time.
Pro Tip
Enable SSR (Server-Side Rendering) with Angular Universal if SEO and first-paint speed are critical.