Modern Web Rendering Strategies: SPA, SSR, SSG, and ISR

The days of just uploading HTML files via FTP are long gone.Today's frontend landscape offers powerful rendering patterns, each with distinct trade-offs.

1. Single Page Applications(SPA)

** Examples:** React(CRA), Vue, Angular.

• ** How it works:** The server sends an empty HTML shell and a massive JavaScript bundle.The browser downloads the JS, builds the UI, and fetches data.
• ** Best for:** Admin dashboards, social networks, highly interactive apps(Gmail, Trello).
• ** Downside:** Poor SEO(search engines see an empty page initially) and slow initial load time.

2. Server - Side Rendering(SSR)

** Examples:** Next.js(Pages router), Remix.

• ** How it works:** Every request goes to the server.The server fetches data, builds the HTML, and sends a fully populated page to the user.
• ** Best for:** Dynamic sites that need SEO(News sites, E - commerce product pages).
• ** Downside:** Higher server load and slower Time to First Byte(TTFB).

3. Static Site Generation(SSG)

** Examples:** Gatsby, Hugo, Next.js(Static Export).

• ** How it works:** You build the site * once * at deployment time.The server is just a CDN serving pre - built HTML files.
• ** Best for:** Blogs, Marketing sites, Documentation.
• ** Downside:** Long build times.If you fix a typo, you have to rebuild the entire site.

The Winner: Hybrid(ISR)

Frameworks like Next.js now allow ** Incremental Static Regeneration(ISR) **.You release a static page(fast), but the server rebuilds it in the background every X minutes.You get the speed of SSG with the freshness of SSR.