Configuration

nuxt.config

The starting point for your Nuxt app remains your nuxt.config file.

Migration

1. You should migrate to the new defineNuxtConfig function that provides a typed configuration schema.
   Nuxt 2Nuxt 3

   Nuxt 2

   export default {  // ...}

   Nuxt 3

   export default defineNuxtConfig({  // ...})

2. If you were using router.extendRoutes you can migrate to the new pages:extend hook:
   Nuxt 2Nuxt 3

   Nuxt 2

   export default {  router: {    extendRoutes (routes) {      //    }  }}

   Nuxt 3

   export default defineNuxtConfig({  hooks: {    'pages:extend' (routes) {      //    }  }})

ESM Syntax

Nuxt 3 is an ESM native framework. Although unjs/jiti provides semi compatibility when loading nuxt.config file, avoid any usage of require and module.exports in this file.

1. Change module.exports to export default
2. Change const lib = require('lib') to import lib from 'lib'

Async Configuration

In order to make Nuxt loading behavior more predictable, async config syntax is deprecated. Consider using Nuxt hooks for async operations.

Dotenv

Nuxt has built-in support for loading .env files. Avoid directly importing it from nuxt.config.

Modules

Nuxt and Nuxt Modules are now build-time-only.

Migration

1. Move all your buildModules into modules.
2. Check for Nuxt 3 compatibility of modules.

TypeScript

It will be much easier to migrate your application if you use Nuxt's TypeScript integration. This does not mean you need to write your application in TypeScript, just that Nuxt will provide automatic type hints for your editor.

You can read more about Nuxt's TypeScript support in the docs.

Migration

1. Create a tsconfig.json with the following content:

   {  "extends": "./.nuxt/tsconfig.json"}

2. Run npx nuxi prepare to generate .nuxt/tsconfig.json.
3. Install Volar following the instructions in the docs.

Vue Changes

There are a number of changes to what is recommended Vue best practice, as well as a number of breaking changes between Vue 2 and 3.

It is recommended to read the Vue 3 migration guide and in particular the breaking changes list.

It is not currently possible to use the Vue 3 migration build with Nuxt 3 RC.

Vuex

Nuxt no longer provides a Vuex integration. Instead, the official Vue recommendation is to use pinia, which has built-in Nuxt support via a Nuxt module. Find out more about pinia here.

If you want to keep using Vuex, you can manually migrate to Vuex 4 following these steps.