Svelte Application Deployment Checklist

Svelte Application Deployment Checklist

SvelteKit offers multiple deployment targets. Here's what to verify before going live.

Choose the Right Adapter

// svelte.config.js
import adapter from '@sveltejs/adapter-node'; // For Node.js servers
// import adapter from '@sveltejs/adapter-vercel';  // For Vercel
// import adapter from '@sveltejs/adapter-static';  // For static hosting

export default {
  kit: {
    adapter: adapter({
      out: 'build',
      precompress: true, // Generates .gz and .br files
    }),
  },
};

• [ ] Adapter matches hosting platform
• [ ] Precompression enabled for static assets
• [ ] SSR configured correctly per route

Build Verification

npm run build
npm run preview  # Test production build locally

• [ ] Production build completes without errors
• [ ] Build output size is reasonable
• [ ] All routes load correctly in preview mode
• [ ] Dynamic imports and code splitting working

Environment Variables

// Only $env/static/public variables are client-accessible
import { PUBLIC_API_URL } from '$env/static/public';

// Server-only variables
import { DATABASE_URL } from '$env/static/private';

• [ ] All environment variables set on hosting platform
• [ ] No private variables exposed to client
• [ ] $env/static used for build-time values
• [ ] $env/dynamic used for runtime values

Error Handling

// src/hooks.server.ts
export function handleError({ error, event }) {
  console.error('Server error:', error);
  return {
    message: 'An unexpected error occurred',
    code: 'INTERNAL_ERROR',
  };
}

• [ ] hooks.server.ts error handler configured
• [ ] hooks.client.ts error handler configured
• [ ] Custom error pages created (+error.svelte)
• [ ] Error tracking with Bugsly for production visibility

Performance

• [ ] Prerendering enabled for static pages
• [ ] Image optimization configured
• [ ] Font loading optimized (preload critical fonts)
• [ ] Third-party scripts loaded asynchronously

Security

• [ ] CSP headers configured in hooks.server.ts
• [ ] CSRF protection enabled
• [ ] Form actions validate input server-side
• [ ] Rate limiting on form actions

Infrastructure

• [ ] Health check endpoint available
• [ ] SSL/TLS configured
• [ ] CDN in front of static assets
• [ ] Monitoring and alerting set up