What is SSG in Next.js: Static Site Generation Explained

SSG in Next.js stands for Static Site Generation, a method where pages are pre-built as static HTML at build time. This means the content is generated once and served quickly to users without server processing on each request.

How It Works

Static Site Generation (SSG) in Next.js works by creating the HTML for your pages ahead of time, during the build process. Imagine baking cookies before guests arrive, so when they come, you just hand them a ready cookie instead of baking it on the spot. This makes the website load very fast because the server just sends the pre-made pages.

Next.js runs your page code once at build time, fetches any needed data, and saves the final HTML. When a user visits the page, the server delivers this static HTML immediately, without running extra code. This is great for pages that don’t change often, like blogs or marketing sites.

Example

This example shows a Next.js page using getStaticProps to fetch data at build time and generate a static page.

javascript

import React from 'react';

export async function getStaticProps() {
  // Simulate fetching data
  const data = { message: 'Hello from SSG!' };
  return {
    props: { data },
  };
}

export default function HomePage({ data }) {
  return <h1>{data.message}</h1>;
}

Output

Hello from SSG!

When to Use

Use SSG when your page content does not change often and you want very fast load times. It is perfect for blogs, documentation, portfolios, and marketing pages where content updates happen during deployments, not on every user visit.

SSG reduces server load and improves SEO because search engines get fully rendered HTML. However, it is not ideal for pages that need to show real-time or user-specific data.

Key Points

• SSG generates pages at build time as static HTML.
• Pages load very fast because no server processing is needed on each request.
• Best for content that changes infrequently.
• Implemented in Next.js using getStaticProps and optionally getStaticPaths.
• Improves SEO and reduces server costs.

Key Takeaways

SSG pre-builds pages as static HTML during the build process for fast delivery.

Use SSG for pages with content that rarely changes, like blogs or marketing sites.

Next.js uses getStaticProps to fetch data at build time for SSG.

SSG improves SEO and reduces server load by serving static files.

Not suitable for pages needing real-time or user-specific data.