Nuxt has long been the gold standard for building full-stack Vue applications. Server-side rendering, file-based routing, auto-imports, and a thriving module ecosystem, it's the framework that makes Vue feel complete. And now, **Nuxt 4** pushes things even further with a leaner project structure, more predictable data fetching, and significant quality-of-life improvements for TypeScript developers. Whether you're starting a new project or upgrading an existing Nuxt 3 app, this guide covers everything you need to hit the ground running. --- ## Why Nuxt 4? Nuxt 3 was a massive leap, the move to Vite, Nitro, the Composition API, and ` ``` ### The `getCachedData` Default Under the hood, `useAsyncData` now ships with a sensible `getCachedData` default. If data was fetched during SSR and is available in the Nuxt payload, it won't be re-fetched on the client unless you explicitly clear it or the key changes. This alone eliminates an entire category of bugs seen in production Nuxt 3 apps. You can still opt into client-side re-fetching when needed: ```ts const { data, refresh } = await useAsyncData('user-profile', () => $fetch('/api/me'), { // Force a refresh on client navigation getCachedData: () => null, } ) ``` --- ## The `shared/` Directory: Cross-Boundary Code One of the most requested features in Nuxt 3 was a clean way to share types and utilities between your Vue app and your Nitro server routes. The `shared/` directory in Nuxt 4 is the official answer. ``` shared/ ├── types/ │ └── post.ts └── utils/ └── formatDate.ts ``` ```ts // shared/types/post.ts export interface Post { id: number title: string publishedAt: string author: string } ``` ```ts // server/api/posts.get.ts import type { Post } from '~~/shared/types/post' export default defineEventHandler((): Post[] => { return [ { id: 1, title: 'Hello Nuxt 4', publishedAt: '2026-01-01', author: 'Daniel' }, ] }) ``` ```vue ``` No more `#imports` hacks or duplicated type definitions. The `~~/` alias resolves to the project root, giving you clean, explicit imports from the shared layer. --- ## Improved TypeScript Experience TypeScript support in Nuxt 4 has been significantly tightened: - **Stricter auto-import types**, generated `.nuxt/types` files are more accurate and update faster during development - **Component prop inference**, TypeScript now correctly infers props from `defineProps` in auto-imported components - **`useRouteParams` and `useRouteQuery` typed helpers**, no more manual casting when reading route parameters ```ts // Typed route params, no more `route.params.id as string` const { id } = useRouteParams<{ id: string }>() // Typed query strings const { page, sort } = useRouteQuery<{ page: string; sort: 'asc' | 'desc' }>() ``` These helpers are thin wrappers, but the TypeScript ergonomics they unlock are genuinely delightful. --- ## Performance: Where Does Nuxt 4 Stand? ```chart { "type": "bar", "data": { "labels": ["Nuxt 3 (cold start)", "Nuxt 4 (cold start)", "Nuxt 3 (HMR)", "Nuxt 4 (HMR)"], "datasets": [ { "label": "Time (ms), Lower is Better", "data": [3400, 2100, 320, 180] } ] }, "options": { "plugins": { "title": { "display": true, "text": "Dev Server Performance: Nuxt 3 vs Nuxt 4" } }, "scales": { "y": { "beginAtZero": true } } } } ``` Nuxt 4's dev server cold start is noticeably faster thanks to improved module resolution and a tighter integration with Vite's dependency pre-bundling. HMR, especially for composables and layouts, is substantially snappier. Production build times are roughly comparable but benefit from Nitro's continued improvements under the hood. --- ## Nuxt 4 vs Nuxt 3: Feature Comparison | Feature | Nuxt 3 | Nuxt 4 | |---|---|---| | Project Structure | Flat root | `app/` subdirectory | | Shared Code (client + server) | Manual workarounds | `shared/` directory | | Data Fetching Deduplication | Opt-in | Default behavior | | TypeScript route params | Manual casting | `useRouteParams` / `useRouteQuery` | | Compatibility Mode |, | `compatibilityVersion: 4` | | Nitro Version | Nitro 2 | Nitro 3 | | Auto-import accuracy | Good | Improved | | Dev Server Cold Start | ~3.4s | ~2.1s | | Module Ecosystem | Mature | Fully compatible | --- ## Migrating from Nuxt 3: Step-by-Step Migrating is intentionally low-friction. Here's the recommended path: ### Step 1, Enable Compatibility Mode ```ts // nuxt.config.ts export default defineNuxtConfig({ future: { compatibilityVersion: 4, }, }) ``` Run your app. Fix any deprecation warnings that surface. ### Step 2, Create the `app/` Directory ```bash mkdir app mv components composables layouts middleware pages plugins app.vue app/ ``` ### Step 3, Move Shared Code Identify any utilities or types used by both your Vue components and your server routes. Move them into `shared/` and update imports to use `~~/shared/`. ### Step 4, Audit Data Fetching With the new deduplication defaults, review any `useAsyncData` or `useFetch` calls that explicitly relied on client re-fetching. Add `getCachedData: () => null` where you intentionally want a client-side refresh. ### Step 5, Run & Test ```bash npx nuxi upgrade npx nuxi dev ``` For most Nuxt 3 projects, the migration takes less than an afternoon. The Nuxt team has gone out of their way to make this a painless upgrade, a far cry from the Nuxt 2 → 3 experience. --- ## The Module Ecosystem: Fully Compatible One concern with any major version bump is whether the module ecosystem keeps up. Nuxt 4 is **fully backward compatible** with all Nuxt 3 modules. The `@nuxt/` official modules (Image, Content, UI, DevTools) have all been updated, and community modules continue to work without changes. ```chart { "type": "doughnut", "data": { "labels": ["Compatible with Nuxt 4", "Needs Minor Update", "Breaking Changes"], "datasets": [ { "label": "Module Ecosystem Compatibility", "data": [85, 12, 3] } ] }, "options": { "plugins": { "title": { "display": true, "text": "Nuxt 4 Module Ecosystem Compatibility (%)" } } } } ``` The vast majority of the ecosystem just works. The small slice requiring updates are mostly niche modules that hooked into internal Nuxt APIs, and their maintainers are actively shipping fixes. --- ## Should You Start New Projects on Nuxt 4 Today? **Yes.** Nuxt 4 is stable, and the team's track record on stability is excellent. The new `app/` structure is better for project organization from day one, and you'll want to be building habits around `shared/` and the improved data fetching defaults rather than learning workarounds that no longer apply. For existing Nuxt 3 projects, the compatibility mode makes the migration risk low. The improvements, especially around data fetching correctness and TypeScript ergonomics, are worth the move. --- ## Wrapping Up Nuxt 4 isn't a rewrite, it's a **graduation**. The framework takes everything that made Nuxt 3 excellent and files off the rough edges that practitioners have been dealing with for the past two years. The new `app/` directory gives large projects room to breathe, the `shared/` layer solves a real pain point for full-stack teams, and the data fetching improvements eliminate an entire class of subtle production bugs. If Vue is your frontend of choice, Nuxt 4 is the best version of the framework yet. Give it a spin. ```bash npx nuxi@latest init my-nuxt4-app cd my-nuxt4-app npx nuxi dev ```

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Nuxt 4: Everything You Need to Know About the Next Generation of the Vue Meta-Framework