next/image tối ưu SEO và performance như thế nào?

next/image tự động handle lazy loading, responsive srcset, WebP conversion, và CLS prevention — 5 tính năng trực tiếp cải thiện Core Web Vitals.

1. Lazy loading mặc định — chỉ load khi gần viewport, giảm initial page weight
2. Responsive images — tự generate srcset với nhiều sizes, browser chọn size phù hợp
3. Format optimization — auto convert sang WebP/AVIF nếu browser hỗ trợ, giảm 30-50% file size
4. Prevent CLS — bắt buộc width/height hoặc fill, tránh layout shift
5. Priority loading — set priority={true} cho LCP image (above-the-fold)

SEO impact: LCP cải thiện (ranking signal), CLS giảm (ranking signal), smaller images = faster page = better crawl experience. Luôn thêm alt text mô tả ảnh cho Google Image Search và accessibility.

next/image automatically handles lazy loading, responsive srcset, WebP conversion, and CLS prevention — 5 features that directly improve Core Web Vitals.

1. Lazy loading by default — images only load when near the viewport, reducing initial page weight
2. Responsive images — automatically generates a srcset at multiple sizes; the browser selects the most appropriate one
3. Format optimization — auto-converts to WebP/AVIF when supported, reducing file size by 30-50%
4. Prevents CLS — requires explicit width/height or fill prop, preventing layout shifts
5. Priority loading — set priority={true} for the LCP image (above the fold)

SEO impact: improved LCP (a ranking signal), reduced CLS (a ranking signal), smaller images mean faster pages and a better crawl experience. Always include a descriptive alt attribute for Google Image Search and accessibility.