Web Performance Optimization: Core Web Vitals 2026

Tiga Metrik Utama

LCP (Largest Contentful Paint) target <2.5 detik. INP (Interaction to Next Paint) target <100ms. CLS (Cumulative Layout Shift) target <0.1.

Image Optimization

Image 60-70% total weight. Gunakan WebP (30% lebih kecil) atau AVIF (50% lebih kecil). Lazy loading native.

CSS Optimization

Inline critical CSS. Non-critical CSS dengan media print lalu onload ganti ke all. Hindari @import.

Font Loading

Gunakan font-display: swap. Preload font utama. Teks tetap terbaca pakai fallback.

JavaScript

Critical script inline. Non-critical defer 3 detik setelah render. Type module untuk async.

Server & Caching

Nginx cache static 1 tahun. Brotli compression. CDN Cloudflare.

Hasil ehary.id

LCP 3.8s ke 1.2s. CLS 0.35 ke 0.02. INP 280ms ke 45ms. PageSpeed Mobile 42 ke 94. Organic traffic naik 180%.

Checklist

Image WebP/AVIF (30-50% weight turun), Critical CSS (0.5-1s LCP turun), JS defer (0.5-2s FID), Brotli (15-25% transfer).