nuxt4-patterns

Nuxt 4 Patterns

Use when building or debugging Nuxt 4 apps with SSR, hybrid rendering, route rules, or page-level data fetching.

When to Activate

• Hydration mismatches between server HTML and client state
• Route-level rendering decisions such as prerender, SWR, ISR, or client-only sections
• Performance work around lazy loading, lazy hydration, or payload size
• Page or component data fetching with useFetch, useAsyncData, or $fetch
• Nuxt routing issues tied to route params, middleware, or SSR/client differences

Hydration Safety

• Keep the first render deterministic. Do not put Date.now(), Math.random(), browser-only APIs, or storage reads directly into SSR-rendered template state.
• Move browser-only logic behind onMounted(), import.meta.client, ClientOnly, or a .client.vue component when the server cannot produce the same markup.
• Use Nuxt's useRoute() composable, not the one from vue-router.
• Do not use route.fullPath to drive SSR-rendered markup. URL fragments are client-only, which can create hydration mismatches.
• Treat ssr: false as an escape hatch for truly browser-only areas, not a default fix for mismatches.

Data Fetching

• Prefer await useFetch() for SSR-safe API reads in pages and components. It forwards server-fetched data into the Nuxt payload and avoids a second fetch on hydration.
• Use useAsyncData() when the fetcher is not a simple $fetch() call, when you need a custom key, or when you are composing multiple async sources.
• Give useAsyncData() a stable key for cache reuse and predictable refresh behavior.
• Keep useAsyncData() handlers side-effect free. They can run during SSR and hydration.
• Use $fetch() for user-triggered writes or client-only actions, not top-level page data that should be hydrated from SSR.
• Use lazy: true, useLazyFetch(), or useLazyAsyncData() for non-critical data that should not block navigation. Handle status === 'pending' in the UI.
• Use server: false only for data that is not needed for SEO or the first paint.
• Trim payload size with pick and prefer shallower payloads when deep reactivity is unnecessary.