Astro vs Eleventy: The Static Site Smackdown

Two modern static site generators battle it out. Astro brings component-driven architecture and partial hydration, while Eleventy sticks to simplicity and data-first templating. Which one deserves your code?

Core Architecture

Astro uses a component-based architecture where you can write components in React, Vue, Svelte, or plain HTML/JS, then ships zero JavaScript by default. Eleventy uses a template-first approach with 11 different templating languages (like Liquid, Nunjucks, Markdown) and focuses on transforming data into HTML through templates.

Performance Approach

Astro's killer feature is partial hydration: you explicitly opt-in components to run JavaScript, shipping minimal JS (often 90% less than traditional SPAs). Eleventy generates pure static HTML with zero runtime JavaScript unless you manually add it—great for simplicity but lacks Astro's smart hydration controls.

Developer Experience

Astro offers modern DX with Vite under the hood, hot module replacement, and TypeScript support out of the box. Eleventy has a simpler, config-over-convention approach with fewer built-in dev tools—you'll likely need to configure your own build pipeline for advanced features.

Data Handling

Eleventy excels at data transformation with global data files, computed data, and pagination built in. Astro handles data through its component system and fetch API, which feels more modern but requires more manual setup for complex data pipelines.

Pricing & Ecosystem

Both are open source and free. Astro has commercial backing from Vercel and a rapidly growing plugin ecosystem. Eleventy is community-driven with fewer official plugins but stable, mature templates. Hosting costs are identical since both output static files.

Gotchas

Astro: The component model can feel over-engineered for simple sites. Eleventy: Lacks built-in component system—you'll use includes/partials which get messy at scale. Both have learning curves: Astro requires understanding hydration strategies, Eleventy requires mastering its data cascade.

Quick Comparison

Factor	astro	eleventy
Default JavaScript Bundle Size	0kb (opt-in hydration only)	0kb (pure static)
Built-in Dev Server Speed	Vite-based, sub-second HMR	Custom server, slower rebuilds
Templating Language Options	.astro + framework components	11 languages (Liquid, Nunjucks, etc.)
Learning Curve for React/Vue Devs	Low (uses familiar component patterns)	High (must learn template languages)
Data Transformation Capabilities	Good (fetch API + frontmatter)	Excellent (global data, pagination, filters)
Plugin Ecosystem Size	150+ official integrations	50+ community plugins
Build Time for 1000 Pages	~15-30 seconds (parallel builds)	~45-60 seconds (sequential by default)
TypeScript Support	First-class, out of the box	Manual configuration required

The Verdict

Use astro if: You're building content sites that need interactive components, want to use React/Vue/Svelte components, or prioritize cutting-edge performance with partial hydration.

Use eleventy if: You need maximum control over data pipelines, prefer template languages over components, or are building simple blogs/documentation sites where Eleventy's simplicity shines.

Consider: Gatsby or Next.js if you need full SSR/ISR capabilities beyond static generation.

The Bottom Line

Astro wins

Astro wins for most projects because its component model, built-in partial hydration, and framework-agnostic approach make it more versatile and future-proof, while Eleventy's simplicity becomes a limitation as projects scale.

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