Key techniques include code splitting, lazy loading, image optimization, caching strategies, and minimizing render-blocking resources.
Frontend performance optimization encompasses various techniques to improve load times and runtime performance. Here's a comprehensive overview of key strategies.
Code Splitting divides your JavaScript bundle into smaller chunks loaded on demand. Route-based splitting loads code only when a route is accessed. Component-based splitting with dynamic imports (React.lazy, import()) loads components when needed.
Lazy Loading defers loading of non-critical resources: images below the fold (loading="lazy"), components not immediately visible, and third-party scripts. Intersection Observer API enables efficient implementation.
Image Optimization includes using modern formats (WebP, AVIF), responsive images (srcset), proper sizing (don't send 2000px images for 200px displays), and image CDNs that optimize on-the-fly.
Caching involves browser caching (Cache-Control headers), service workers for offline capability and cache control, and CDN caching for static assets. Use content hashing in filenames for cache busting.
Bundle Optimization means tree shaking (removing unused code), minification, compression (Brotli/gzip), and analyzing bundle size to identify large dependencies.
Rendering Performance includes avoiding layout thrashing (batch DOM reads/writes), using CSS containment, debouncing/throttling event handlers, using requestAnimationFrame for animations, and virtualizing long lists.
Monitoring with Web Vitals, Lighthouse, and real user monitoring helps identify issues. Remember: measure before optimizing, focus on user-perceived performance, and optimize the critical path first.
Key techniques include code splitting, lazy loading, image optimization, caching strategies, and minimizing render-blocking resources.
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