Rendering Strategies

Angular supports multiple rendering strategies to optimize for SEO, performance, and interactivity.

1. Client-Side Rendering (CSR)

**Default Strategy.** Content is rendered entirely in the browser.

• **Use case**: Interactive dashboards, internal tools.
• **Pros**: Simplest to configure, low server cost.
• **Cons**: Poor SEO, slower initial content visibility (must wait for JS).

2. Static Site Generation (SSG / Prerendering)

Content is pre-rendered into static HTML files at **build time**.

• **Use case**: Marketing pages, blogs, documentation.
• **Pros**: Fastest initial load, excellent SEO, CDN-friendly.
• **Cons**: Requires rebuild for content updates, not for user-specific data.

3. Server-Side Rendering (SSR)

Content is rendered on the server for the **initial request**. Subsequent navigations happen client-side (SPA style).

• **Use case**: E-commerce product pages, news sites, personalized dynamic content.
• **Pros**: Excellent SEO, fast initial content visibility.
• **Cons**: Requires a server (Node.js), higher server cost/latency.

Hydration

Hydration is the process of making server-rendered HTML interactive in the browser.

• **Full Hydration**: The entire app becomes interactive at once.
• **Incremental Hydration**: (Advanced) Parts become interactive as needed using `@defer` blocks.
• **Event Replay**: Captures and replays user events that happened before hydration finished.

Decision Matrix

| Requirement | Strategy | | :------------------------------ | :------------------- | | **SEO + Static Content** | SSG | | **SEO + Dynamic Content** | SSR | | **No SEO + High Interactivity** | CSR | | **Mixed** | Hybrid (Route-based) |