Caching

App Router uses multi-level caching: full-route, RSC, and fetch cache. Cache choices drive SSG, ISR, or SSR.

Full-route cache

• Caches HTML + RSC payload.
• Auto-enabled when no dynamic inputs are used.
• Controls: export const dynamic = "force-static", export const revalidate = N.
• Good for marketing pages, blogs, docs.

RSC cache

• Caches server component output.
• Skipped when reading cookies/headers, using no-store, or serving user-specific data.

Fetch cache

• Each fetch() in RSC has a cache policy.
• cache: "force-cache" (default), cache: "no-store", next: { revalidate: N }.

fetch("https://api.example.com", { next: { revalidate: 60 } });

How levels interact

• Fetch cache → RSC cache → full-route cache.
• Any dynamic element punches through to SSR.