Next.js 16.3 is now fully supported on Vercel, bringing measurable performance improvements: 45% fewer prefetch requests, 17% fewer CDN requests and 24% fewer bytes transferred for static content, and ~2x faster p99 route resolution for large sites. Key platform changes include immutable static assets reused across deployments (cutting re-upload time by up to 30%), a revamped route metadata serving layer using JSONL shards for ~10x fewer cache misses, and new observability features for prefetch requests, ISR revalidations, and Partial Prerendering (PPR). PPR observability is launching today, letting developers see which requests serve static vs. dynamic content. The routing metadata improvements benefit all frameworks using Vercel's Build Output API, not just Next.js.
