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

   export default {
     // ...
   }
   

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

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

3. If you were using router.routeNameSplitter you can achieve same result by updating route name generation logic in the new pages:extend hook:
   Nuxt 2Nuxt 3

   export default {
     router: {
       routeNameSplitter: '/'
     }
   }
   

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.
3. If you have any local modules pointing to a directory you should update this to point to the entry file:

  export default defineNuxtConfig({
    modules: [
-     '~/modules/my-module'
+     '~/modules/my-module/index'
    ]
  })

Directory Changes

The static/ (for storing static assets) has been renamed to public/. You can either rename your static directory to public, or keep the name by setting dir.public in your nuxt.config.

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.

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.

A simple way to provide global state management with pinia would be:

Install the @pinia/nuxt module:

yarn add pinia @pinia/nuxt

Enable the module in your nuxt configuration:

import { defineNuxtConfig } from 'nuxt/config';

export default defineNuxtConfig({
  modules: ['@pinia/nuxt']
})

Create a store folder at the root of your application:

import { defineStore } from 'pinia'

export const useMainStore = defineStore('main', {
  state: () => ({
    counter: 0,
  }),
  actions: {
    increment() {
      // `this` is the store instance
      this.counter++
    },
  },
})

Create a plugin file to globalize your store:

import { useMainStore } from '~/store'

export default defineNuxtPlugin(({ $pinia }) => {
  return {
    provide: {
      store: useMainStore($pinia)
    }
  }
})

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

Once it's done you will need to add the following plugin to your Nuxt app:

import store from '~/store'

export default defineNuxtPlugin(nuxtApp => {
  nuxtApp.vueApp.use(store);
})

For larger apps, this migration can entail a lot of work. If updating Vuex still creates roadblocks, you may want to use the community module: nuxt3-vuex-module, which should work out of the box.