Next.js Performance
Real performance optimization for Next.js App Router. Not "add lazy loading" — actual diagnosis workflows, rendering-strategy decisions, and production caching patterns.
Version baseline (as of Jul 2026): Next.js 16.x is current (16.3 shipped Jun 29, 2026; docs track 16.2.x); examples target Next.js 15/16. Where 15 and 16 diverge (image priority→preload, minimumCacheTTL default, unstable_cache→'use cache', removed NextRequest.geo), both are called out. Verify versions/APIs at https://nextjs.org/docs and release notes at https://nextjs.org/blog. For SEO/metadata performance see the sibling seo-geo skill.
Reference guide
Read only the references needed for the current request:
- 1. Core Web Vitals — What Actually Causes Problems: references/1-core-web-vitals-what-actually-causes-problems.md
- 2. Rendering Strategy Decision Matrix: references/2-rendering-strategy-decision-matrix.md
- 3. Image Optimization: references/3-image-optimization.md
- 4. Bundle Analysis & Tree Shaking: references/4-bundle-analysis-tree-shaking.md
- 5. Edge Functions & Middleware: references/5-edge-functions-middleware.md
- 6. Font Loading: references/6-font-loading.md
- 7. Caching Strategies: references/7-caching-strategies.md
- 8. Performance Audit Workflow: references/8-performance-audit-workflow.md
- 9. Production Checklist: references/9-production-checklist.md
- Bundle: references/bundle.md
- Images: references/images.md
- Rendering: references/rendering.md
- Fonts: references/fonts.md
- Caching: references/caching.md
- Third-Party: references/third-party.md
- Monitoring: references/monitoring.md