The differences between Angular SSR (Server-Side Rendering) and Angular SSG (Static Site Generation) can be summarized as follows

 

1. When HTML is Generated

• SSR: HTML is dynamically generated on each request by the server. The server processes the request, fetches data, and renders the page in real-time.

• SSG: HTML is pre-rendered at build time. All pages are generated upfront during the build process and stored as static files.

2. Use Case

• SSR: Best for dynamic applications with real-time or user-specific content (e.g., dashboards, e-commerce product pages). Ideal when data changes frequently.

• SSG: Best for static content that rarely changes (e.g., blogs, landing pages, documentation). Suitable for SEO-heavy sites with pre-defined content.

3. Performance

• SSR: Slightly slower initial response due to server processing per request, but ensures fresh content. Requires a Node.js server.

• SSG: Faster delivery since pre-built HTML is served directly. Can leverage CDN caching for global scalability.

4. Data Handling

• SSR: Fetches data on every request, ensuring up-to-date content (e.g., live stock prices, user sessions).

• SSG: Fetches data once at build time. Content becomes stale until the site is rebuilt (requires redeployment for updates).

5. Deployment

• SSR: Requires a server or cloud platform that supports Node.js (e.g., Firebase Cloud Functions, AWS EC2).

• SSG: Can be hosted on static hosting services (e.g., GitHub Pages, Netlify, Vercel) with no server overhead.

6. Implementation in Angular

• Both use Angular Universal but with different workflows:

• SSR: Enabled via server-side-rendering schematic. Uses app.server.module.ts to handle dynamic rendering.

• SSG: Achieved via prerendering (e.g., ng run app:prerender). Generates static HTML files for specified routes during build.

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Example Commands

• SSR: ng add @nguniversal/express-engine (sets up a Node.js server for on-demand rendering).

• SSG: ng run your-app:prerender (pre-renders static HTML files at build time).

When to Choose?

• Choose SSR if your app needs real-time data, user authentication, or frequent content updates.

• Choose SSG if your content is static, SEO is critical, and you want low-cost, high-performance hosting.