AstroComparisonBeginner · 4 min read

Astro vs Gatsby: Key Differences and When to Use Each

Astro is a modern static site builder focused on delivering fast, minimal JavaScript by default, while Gatsby is a React-based framework that pre-renders pages and uses GraphQL for data fetching. Astro supports multiple UI frameworks and partial hydration, whereas Gatsby relies heavily on React and plugins. Choose Astro for lightweight, flexible sites and Gatsby for React-centric, plugin-rich projects.

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Quick Comparison

Here is a quick side-by-side look at key factors between Astro and Gatsby.

Factor	Astro	Gatsby
Core Technology	Framework-agnostic, supports React, Vue, Svelte, etc.	React-based
Rendering	Static site generation with partial hydration	Static site generation with full React hydration
JavaScript Output	Minimal by default, ships only needed JS	Ships full React runtime on client
Data Fetching	Flexible, supports multiple sources without GraphQL	Uses GraphQL for data querying
Plugin Ecosystem	Growing but smaller	Mature and extensive
Use Case	Fast, content-focused sites with less JS	Complex React apps with rich interactivity

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Key Differences

Astro is designed to minimize JavaScript sent to the browser by default. It achieves this by rendering most content to static HTML and only hydrating interactive components when needed. This partial hydration approach means faster load times and better performance, especially for content-heavy sites.

In contrast, Gatsby builds React apps that pre-render pages at build time but hydrate the entire React app on the client. This results in more JavaScript sent to the browser, which can impact performance but allows for rich interactivity and React ecosystem benefits.

Astro supports multiple UI frameworks in the same project, letting you mix React, Vue, Svelte, or plain HTML components. Gatsby is tightly coupled to React and uses GraphQL to fetch data from various sources, which adds complexity but powerful data querying capabilities.

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Code Comparison

Here is how you create a simple page with a button that shows an alert when clicked in Astro.

astro

---
// Astro component
---
<html lang="en">
  <head>
    <title>Astro Button Example</title>
  </head>
  <body>
    <button on:click={() => alert('Hello from Astro!')}>Click me</button>
  </body>
</html>

Output

<button>Click me</button> (clicking shows alert 'Hello from Astro!')

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Gatsby Equivalent

This is the equivalent React component in Gatsby that shows an alert on button click.

jsx

import React from 'react';

export default function ButtonExample() {
  return (
    <button onClick={() => alert('Hello from Gatsby!')}>Click me</button>
  );
}

Output

<button>Click me</button> (clicking shows alert 'Hello from Gatsby!')

🎯

When to Use Which

Choose Astro when you want a fast, lightweight site with minimal JavaScript and the flexibility to use multiple UI frameworks. It is ideal for blogs, marketing sites, and content-heavy projects where performance is key.

Choose Gatsby when you need a React-based framework with a mature plugin ecosystem and powerful data fetching via GraphQL. It suits complex web apps requiring rich interactivity and integration with many data sources.

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Key Takeaways

Astro minimizes client JavaScript by default using partial hydration for better performance.

Gatsby is React-based and uses GraphQL, shipping full React runtime on the client.

Astro supports multiple UI frameworks; Gatsby is React-only.

Choose Astro for fast, content-focused sites; choose Gatsby for complex React apps.

Both generate static sites but differ in client-side interactivity and ecosystem.