React is a JavaScript library for building user interfaces. It uses a Virtual DOM for efficient UI updates but defaults to Client-Side Rendering (CSR). This means the server sends a nearly empty HTML file, and JavaScript renders the content in the browser, creating the "blank canvas" problem for crawlers.

Google's two-wave indexing process can struggle with CSR. The first wave sees an empty page. The second, resource-intensive rendering wave may be delayed or incomplete, leading to poor indexing, missed metadata (title, description), and invisible internal links.

The Meta-Framework Solution

The complexity of manually implementing server rendering led to the rise of meta-frameworks, which is now the officially recommended approach by the React team.

• Server-Side Rendering (SSR): Renders components on a server for every request, sending full HTML to the browser. This is the most robust solution for dynamic sites. Frameworks like Next.js provide this out-of-the-box.
• Static Site Generation (SSG): Pre-renders every page into static HTML at build time. Ideal for content-heavy sites like blogs for maximum performance.

Metadata and Routing

Use react-helmet-async to manage head tags like <title> and <meta> on a per-page basis. Use React Router with its History API for clean, crawlable URLs.

Performance

Performance is critical for SEO. Use code-splitting with React.lazy and Suspense to break up large bundles, and analyze bundle size to remove unnecessary dependencies.

• Do not build a public-facing website with client-side-only React.
• Choose a meta-framework like Next.js or Remix for any new project.
• Implement on-page SEO fundamentals: use react-helmet-async for metadata and add structured data.
• Prioritize performance: aggressively code-split, reduce bundle size, and optimize images.