Next.js 16 vs Astro 5
Real-world performance comparison based on identical SaaS dashboard implementations.
Next.js 16
Vercel
Next.js deployed on its native platform—the way it was designed to run. Vercel's infrastructure is purpose-built for Next.js, providing automatic edge caching, instant rollbacks, and preview deployments for every git push. ISR (Incremental Static Regeneration) works seamlessly on Vercel with on-demand revalidation APIs and automatic cache invalidation across their global edge network. Edge Functions run your middleware in 30+ regions with sub-millisecond cold starts. This deployment demonstrates Next.js at its most optimized, with Vercel handling image optimization, analytics, and Web Vitals monitoring automatically.
Astro 5
VPS
The web framework for content-driven websites. Astro's revolutionary Islands architecture ships zero JavaScript by default—interactive components hydrate independently only where needed, dramatically reducing bundle sizes. Astro 5 introduces Content Layer for type-safe content collections, Server Islands for mixing static and dynamic content, and improved build performance. The framework is UI-agnostic: use React, Vue, Svelte, Solid, or vanilla JS components in the same project. Perfect for marketing sites, documentation, blogs, and any content-heavy application where performance matters. Astro consistently achieves perfect Lighthouse scores with minimal effort.
Performance Metrics
Lower is better for all metrics. Green indicates the faster framework.
| Metric | Next.js 16 | Astro 5 | Winner |
|---|---|---|---|
| TTFB (p50) | 44.7ms | 50.5ms | ◀ |
| TTFB (p95) | 44.86ms | 52.23ms | ◀ |
| LCP (p50) | 62ms | 80ms | ◀ |
| LCP (p95) | 70.2ms | 86.2ms | ◀ |
| CLS | 0 | 0 | = |
| TBT | 0 ms | 0 ms | = |
| LCP → TTFB | N/A | 214 ms | - |
| LCP → Load Delay | N/A | 0 ms | - |
| LCP → Load Duration | N/A | 0 ms | - |
| LCP → Render Delay | N/A | 535 ms | - |
| Performance Score | 96 | 99 | ▶ |
| SEO Score | 100 | 92 | ◀ |
| Accessibility Score | 88 | 79 | ◀ |
| Best Practices Score | 100 | 100 | = |
LLM Understanding (Claude Opus 4.5)
How efficiently Claude Opus 4.5 understands the codebase. Based on exploration + validation tests.
| Metric | Next.js 16 | Astro 5 | Winner |
|---|---|---|---|
| Exploration Time | 3883ms | 3955ms | ◀ |
| Exploration Tokens | 3963 | 2756 | ▶ |
| Files Examined | 11 | 8 | ▶ |
| Validation Accuracy | 100% | 86% | ◀ |
| Time Per File | 353ms | 494ms | ◀ |
| Tokens Per File | 3245 | 3496 | ◀ |
| Efficiency Score | 43.28 | 33.49 | ◀ |
LLM Understanding (Claude Haiku 4.5)
How efficiently Claude Haiku 4.5 understands the codebase. Based on exploration + validation tests.
| Metric | Next.js 16 | Astro 5 | Winner |
|---|---|---|---|
| Exploration Time | 3029ms | 2240ms | ▶ |
| Exploration Tokens | 3991 | 2764 | ▶ |
| Files Examined | 11 | 8 | ▶ |
| Validation Accuracy | 99% | 81% | ◀ |
| Time Per File | 275ms | 280ms | ◀ |
| Tokens Per File | 3225 | 3474 | ◀ |
| Efficiency Score | 55.84 | 49.18 | ◀ |
Build Metrics
| Metric | Next.js 16 | Astro 5 | Winner |
|---|---|---|---|
| Bundle Size (JS) | 613.3KB | 242.7KB | ▶ |
| Bundle Size (CSS) | 23.3KB | 22.6KB | ▶ |
| Build Time | 0s | 0s | = |
| Dependencies | 18 | 18 | = |
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