Nuxt Production

<!-- If you relied on the placeholder <div> for layout -->
<ClientOnly>
  <MyComponent />
  <template #fallback>
    <div class="placeholder" style="min-height: 200px"></div>
  </template>
</ClientOnly>

// nuxt.config.ts
export default defineNuxtConfig({
  experimental: {
    clientNodePlaceholder: false
  }
})

// WRONG
nuxtApp.callHook('my:hook', data).then(() => { ... })

// CORRECT
await nuxtApp.callHook('my:hook', data)

<!-- Non-deterministic values -->
<script setup>
const id = useState('random-id', () => Math.random())
</script>

<!-- Browser APIs -->
<script setup>
const width = ref(0)
onMounted(() => {
  width.value = window.innerWidth
})
</script>

<!-- ClientOnly component -->
<template>
  <ClientOnly>
    <MyMapComponent />
    <template #fallback>
      <div class="skeleton">Loading map...</div>
    </template>
  </ClientOnly>
</template>

<script setup>
const HeavyChart = defineAsyncComponent(() =>
  import('~/components/HeavyChart.vue')
)
</script>

<script setup>
const LazyComponent = defineLazyHydrationComponent(
  'visible',
  () => import('./HeavyComponent.vue')
)

const InteractiveComponent = defineLazyHydrationComponent(
  'interaction',
  () => import('./InteractiveComponent.vue')
)

const IdleComponent = defineLazyHydrationComponent(
  'idle',
  () => import('./IdleComponent.vue')
)
</script>

export default defineNuxtConfig({
  routeRules: {
    '/': { prerender: true },
    '/about': { prerender: true },
    '/blog/**': { swr: 3600 },
    '/products/**': { isr: 3600 },
    '/dashboard/**': { ssr: false },
    '/static/**': {
      headers: { 'Cache-Control': 'public, max-age=31536000' }
    }
  }
})

<template>
  <NuxtImg
    src="/images/hero.jpg"
    alt="Hero image"
    width="800"
    height="400"
    loading="lazy"
    placeholder
    format="webp"
  />

  <NuxtPicture
    src="/images/product.jpg"
    alt="Product"
    sizes="sm:100vw md:50vw lg:400px"
    :modifiers="{ quality: 80 }"
  />
</template>

bun add -d @nuxt/test-utils vitest @vue/test-utils happy-dom

// vitest.config.ts
import { defineVitestConfig } from '@nuxt/test-utils/config'

export default defineVitestConfig({
  test: {
    environment: 'nuxt',
    environmentOptions: {
      nuxt: {
        domEnvironment: 'happy-dom'
      }
    }
  }
})

import { describe, it, expect } from 'vitest'
import { mountSuspended } from '@nuxt/test-utils/runtime'
import UserCard from '~/components/UserCard.vue'

describe('UserCard', () => {
  it('renders user name', async () => {
    const wrapper = await mountSuspended(UserCard, {
      props: {
        user: { id: 1, name: 'John Doe', email: '[email protected]' }
      }
    })

    expect(wrapper.text()).toContain('John Doe')
  })
})

import { mockNuxtImport } from '@nuxt/test-utils/runtime'

mockNuxtImport('useFetch', () => {
  return () => ({
    data: ref({ users: [{ id: 1, name: 'John' }] }),
    pending: ref(false),
    error: ref(null)
  })
})

bun run build
bunx wrangler pages deploy .output/public

export default defineNuxtConfig({
  nitro: { preset: 'cloudflare_pages' }
})

export default defineNuxtConfig({
  nitro: { preset: 'cloudflare_module' }
})

// Vercel
export default defineNuxtConfig({
  nitro: { preset: 'vercel' }
})

// Netlify
export default defineNuxtConfig({
  nitro: { preset: 'netlify' }
})

bun add @nuxthub/core

export default defineNuxtConfig({
  modules: ['@nuxthub/core'],
  hub: {
    database: true,
    kv: true,
    blob: true,
    cache: true
  }
})

{
  "devDependencies": {
    "nuxt": "^5.0.0"
  }
}

// nuxt.config.ts
export default defineNuxtConfig({
  future: {
    compatibilityVersion: 5
  }
})

// Before (Nuxt 4)
import { createError } from 'h3'
throw createError({ statusCode: 404, statusMessage: 'Not Found' })

// After (Nuxt 5)
import { HTTPError } from 'nitro/h3'
throw new HTTPError({ status: 404, statusText: 'Not Found' })

// Before (Nuxt 4)
const path = event.path
event.node.res.statusCode = 200
setResponseHeader(event, 'x-custom', 'value')
const config = useRuntimeConfig(event)

// After (Nuxt 5)
const path = event.url.pathname
event.res.status = 200
event.res.headers.set('x-custom', 'value')
const config = useRuntimeConfig()

// Before (Nuxt 4)
export default defineNuxtConfig({
  vite: {
    build: {
      rollupOptions: { ... }
    }
  }
})

// After (Nuxt 5) - use rolldownOptions
export default defineNuxtConfig({
  vite: {
    build: {
      rolldownOptions: { ... }
    }
  }
})

// Before
routeRules: {
  '/old': { redirect: { to: '/new', statusCode: 302 } }
}

// After
routeRules: {
  '/old': { redirect: { to: '/new', status: 302 } }
}

// Before
import { defineEventHandler, getQuery } from 'h3'

// After
import { defineEventHandler, getQuery } from 'nitro/h3'
// Or rely on auto-imports (no import needed)

// Remove these from nuxt.config.ts
export default defineNuxtConfig({
  experimental: {
    externalVue: false,  // REMOVED - delete this
    viteEnvironmentApi: true,  // REMOVED - always enabled
  }
})

# Only if your project uses .jsx/.tsx files
bun add -D @vitejs/plugin-vue-jsx

// Before
nuxtApp.callHook('my:hook', data).then(() => { ... })

// After
await nuxtApp.callHook('my:hook', data)

// WRONG
const width = window.innerWidth

// CORRECT
if (import.meta.client) {
  const width = window.innerWidth
}

// Or use onMounted
onMounted(() => {
  const width = window.innerWidth
})

// WRONG
const id = Math.random()
const time = Date.now()

// CORRECT
const id = useState('id', () => Math.random())
const time = useState('time', () => Date.now())

rm -rf .nuxt .output node_modules/.vite && bun install