Build Tooling

We use the following build tools by default:

Vite or webpack
Rollup
PostCSS
esbuild

For this reason, most of your previous build configuration in nuxt.config will now be ignored, including any custom babel configuration.

If you need to configure any of Nuxt's build tools, you can do so in your nuxt.config, using the new top-level vite, webpack and postcss keys.

In addition, Nuxt ships with TypeScript support. Find out more.

Steps

Remove @nuxt/typescript-build and @nuxt/typescript-runtime from your dependencies and modules.
Remove any unused babel dependencies from your project.
Remove any explicit core-js dependencies.
Migrate require to import.

Runtime Config

If you wish to reference environment variables within your Nuxt 3 app, you will need to use runtime config.

Server

In a built Nuxt 3 application, there is no runtime Nuxt dependency. That means your site will be highly performant, and ultra-slim. But it also means you can no longer hook into runtime Nuxt server hooks.