Building with SvelteKit: A Modern Web Framework

SvelteKit has rapidly become one of my favorite frameworks for building web applications. After working with it for several months, I want to share why it’s worth your attention and how it solves common web development challenges.

What is SvelteKit?

SvelteKit is a framework built on top of Svelte that provides:

• File-based routing - Intuitive URL structure
• Server-side rendering (SSR) - Better SEO and performance
• Static site generation (SSG) - Pre-render pages at build time
• Progressive enhancement - Works with or without JavaScript
• Edge deployment - Deploy to the edge with adapters

Why Choose SvelteKit?

1. Developer Experience

The DX is phenomenal. Let me show you a simple component:

<script>
  let count = $state(0);
</script>

<button onclick={() => count++}>
  Clicked {count} {count === 1 ? 'time' : 'times'}
</button>

That’s it. No useState, no complex state management - just reactive variables that work intuitively.

2. File-Based Routing

Create a file, get a route. It’s that simple:

src/routes/
├── +page.svelte          → /
├── about/
│   └── +page.svelte      → /about
└── blog/
    ├── +page.svelte      → /blog
    └── [slug]/
        └── +page.svelte  → /blog/:slug

3. Server Load Functions

Fetch data on the server before rendering:

// +page.server.ts
export const load = async ({ params }) => {
  const post = await getPost(params.slug);
  
  return {
    post
  };
};

This data is automatically available in your component - no client-side fetching needed!

Building a Real Feature

Let’s build a simple blog post loader with TypeScript:

// src/routes/blog/[slug]/+page.server.ts
import { error } from '@sveltejs/kit';
import type { PageServerLoad } from './$types';

export const load: PageServerLoad = async ({ params }) => {
  try {
    const post = await import(`../${params.slug}.md`);
    
    return {
      metadata: post.metadata,
      content: post.default
    };
  } catch (e) {
    throw error(404, 'Post not found');
  }
};

And the page component:

<script lang="ts">
  import type { PageData } from './$types';
  
  let { data }: { data: PageData } = $props();
</script>

<article>
  <h1>{data.metadata.title}</h1>
  <svelte:component this={data.content} />
</article>

Performance Benefits

SvelteKit compiles your components to vanilla JavaScript with no runtime overhead. This means:

• Smaller bundle sizes - Only ship what you need
• Faster page loads - Less JavaScript to parse
• Better Core Web Vitals - Improved performance metrics

Here’s a comparison of bundle sizes for a simple todo app:

Framework	Bundle Size
React	~40KB
Vue	~30KB
Svelte	~3KB

Note: Sizes approximate, gzipped

Deployment Made Easy

SvelteKit adapters make deployment seamless:

// svelte.config.js
import adapter from '@sveltejs/adapter-cloudflare';

export default {
  kit: {
    adapter: adapter()
  }
};

Deploy to:

• Cloudflare Pages/Workers
• Vercel
• Netlify
• Node servers
• Static hosting

Things to Watch Out For

SvelteKit isn’t perfect. Some gotchas:

1. Smaller ecosystem - Fewer third-party libraries than React
2. Learning curve - New concepts if coming from traditional SPAs
3. Breaking changes - Still evolving (though stable now)

Conclusion

SvelteKit offers an excellent balance of developer experience, performance, and flexibility. If you’re starting a new project, I highly recommend giving it a try.

The combination of:

• Intuitive syntax
• Built-in SSR/SSG
• Great TypeScript support
• Edge-ready deployment

…makes it a compelling choice for modern web development.

Resources

• SvelteKit Documentation
• Svelte Tutorial
• SvelteKit Examples

Have you tried SvelteKit? I’d love to hear your thoughts and experiences! 🚀