Build & Deploy with SvelteKit Adapters

In Next.js you control the output format with output in next.config.js ('export' for static, default for Node server) and choose a deployment platform by following its docs. SvelteKit takes a more explicit approach: you install an adapter package and reference it in svelte.config.js. The adapter determines what npm run build produces — a static site, a Node.js server, a Vercel edge function bundle, and so on.

Config file comparison

// next.config.js
/** @type {import('next').NextConfig} */
const nextConfig = {
  output: 'export', // static export
};
module.exports = nextConfig;

// svelte.config.js
import adapter from '@sveltejs/adapter-static';
import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';

/** @type {import('@sveltejs/kit').Config} */
const config = {
  preprocess: vitePreprocess(),
  kit: {
    adapter: adapter({
      fallback: '404.html',
    }),
  },
};

export default config;

Available adapters

Adapter	Equivalent	Use case
`@sveltejs/adapter-static`	Next.js `output: 'export'`	Fully static — deploy to any CDN (Netlify, GitHub Pages, S3)
`@sveltejs/adapter-auto`	—	Auto-detects Vercel, Netlify, Cloudflare automatically
`@sveltejs/adapter-node`	Next.js standalone server	Node.js server (Dockerfile, VPS, Railway)
`@sveltejs/adapter-vercel`	Vercel-specific Next.js deploy	Explicit Vercel deployment with edge/serverless config

Build and preview commands

# Build for production (output depends on adapter)
npm run build

# Preview the production build locally
npm run preview

These map directly to next build and next start / vite preview.

GitHub Actions CI

React/Vite project:

name: CI
on: [push, pull_request]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npm run build
      - run: npm test -- --watchAll=false

SvelteKit project:

name: CI
on: [push, pull_request]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npm run check
      - run: npm run build
      - run: npm run test

The key additions in the SvelteKit workflow are npm run check (runs svelte-check for type errors before building) and npm run test (runs Vitest).

Installing an adapter

# Static
npm install --save-dev @sveltejs/adapter-static

# Auto (recommended for most deployments)
npm install --save-dev @sveltejs/adapter-auto

# Node server
npm install --save-dev @sveltejs/adapter-node

# Vercel
npm install --save-dev @sveltejs/adapter-vercel