Astro vs SvelteKit for Solo Developers

Quick Comparison

Astro Overview

Astro is built for content. It ships zero JavaScript to the browser by default, renders everything to static HTML, and uses an "islands" architecture for selective interactivity. Content collections give you type-safe markdown and MDX. You can drop in React, Vue, or Svelte components wherever you need them.

I run my blog on Astro, and the development experience is fantastic. Pages load instantly because there's no JavaScript to parse. MDX lets me mix components with content. Build times are fast. And the framework stays out of my way. I write content, Astro generates the fastest possible pages.

Astro also supports SSR for dynamic routes and API endpoints, so it's not strictly limited to static sites. But its sweet spot remains content-heavy projects where performance and SEO are priorities. The island architecture is clever: most of your page is static HTML, and only the interactive bits (a search bar, a newsletter form) hydrate as JavaScript.

SvelteKit Overview

SvelteKit is a full-stack application framework built on Svelte. File-based routing, server-side rendering, form actions, API endpoints, and the best progressive enhancement in the framework ecosystem. It compiles Svelte components to optimized vanilla JavaScript, resulting in small bundles and fast apps.

SvelteKit excels at interactive applications. User dashboards, data-heavy apps, forms with complex validation, real-time features. The form actions system handles mutations elegantly, with progressive enhancement meaning your forms work even without JavaScript. The load function pattern makes data fetching predictable and type-safe.

The Svelte ecosystem is smaller than React's but growing. You'll find fewer UI component libraries and third-party integrations. For solo developers who enjoy building things from scratch, this is fine. For those who want to npm install their way to a finished product, SvelteKit requires more custom work.

Key Differences

Primary use case. This is the key distinction. Astro is optimized for content-first sites. SvelteKit is optimized for interactive applications. A blog, documentation site, or marketing page is Astro's home turf. A SaaS dashboard, social platform, or data-heavy app is SvelteKit territory.

JavaScript in the browser. Astro ships zero JS by default and adds it only for interactive islands. SvelteKit ships a (small) Svelte runtime plus your compiled components. For content sites, Astro's approach gives you better performance. For apps that need interactivity on every page, SvelteKit's approach makes more sense.

Content handling. Astro's content collections are purpose-built for managing markdown, MDX, and structured content. Schema validation, type generation, and collection queries make working with content a joy. SvelteKit has mdsvex for markdown but no equivalent built-in content system. You'll need to build your own.

Application features. SvelteKit has form actions, server hooks, progressive enhancement, and a mature routing system designed for application development. Astro can handle dynamic routes and API endpoints, but it's not designed for complex application logic. If your project has authenticated users, complex forms, and real-time features, SvelteKit is the better fit.

Component flexibility. Astro lets you use React, Vue, Svelte, Preact, and Solid components in the same project. SvelteKit is Svelte-only. If you want to reuse components from different frameworks or gradually migrate, Astro gives you that flexibility.

When to Choose Astro

• You're building a blog, documentation site, or marketing page
• Content is the primary focus, with limited interactivity
• You want perfect Lighthouse scores without optimization effort
• You need to mix components from different frameworks
• SEO and page load speed are your top priorities

When to Choose SvelteKit

• You're building an interactive web application
• Your project needs authentication, forms, and user sessions
• You want progressive enhancement for robust form handling
• You need real-time features or complex client-side state
• You're building a SaaS product or dashboard

The Verdict

The answer depends entirely on what you're building. Both score 9/10 for solo developers, but they solve different problems.

Building a blog, portfolio, docs site, or marketing page? Astro. No contest. It's purpose-built for content, ships zero JS, and generates the fastest possible pages. You'd be fighting against SvelteKit to achieve what Astro does by default.

Building a web application with user accounts, forms, dashboards, and interactivity? SvelteKit. It's designed for application development with the best DX in the business. Astro's island architecture works for interactive widgets, but it's not the right tool for full application development.

I use both. Astro for content, SvelteKit for applications. That's the right answer for most solo developers.