Client-Side Rendering (CSR) vs Server-Side Rendering (SSR)

Overview

• Client: The device/user requesting the page.
• Server/Hosting: Where the website's code is stored and executed.
• Request: Client asks for a webpage.
• Response: Server sends back the requested webpage.

Client-Side Rendering (CSR)

• Process:
  1. Client requests webpage from the server.
  2. Server sends back an empty HTML file with embedded JavaScript (JS).
  3. Upon receiving, client's browser runs the JS to fill the HTML content dynamically.
• Characteristics:
  • Initial HTML received is essentially empty except for JS scripts.
  • JS executed on the client-side fills the content (DOM manipulation).
• Advantages:
  • Faster client-side navigation as all JS pages are preloaded to the client.
  • Pages load faster after the initial load because navigation doesn’t require new server requests.
• Disadvantages:
  • Initial load is heavier and slower due to the large amount of JS sent at once.
  • Poor SEO performance as crawlers don’t typically execute JS, resulting in empty content indexing.

Server-Side Rendering (SSR)

• Process:
  1. Client requests webpage from the server.
  2. Server processes the HTML including JS executions and sends back a fully-formed HTML page.
• Characteristics:
  • Received HTML content is prepopulated by the server-side processes before being sent to the client.
• Advantages:
  • Faster initial page load as HTML is already populated when sent.
  • Better SEO performance due to fully-formed HTML that is easily indexed by search engines.
• Disadvantages:
  • Slower client-side navigation as it requires new requests to the server for every page change.

Detailed Comparison

CSR

• Client Navigation:
  • Faster after the first load. No need to communicate with the server for subsequent pages.
• Initial Load:
  • Heavier because the client downloads and executes all scripts required for all pages at once.

SSR

• Client Navigation:
  • Slower because each page change requires a new server request.
• Initial Load:
  • Faster because server sends only the requested content, not the entire application scripts.

SEO Impact

• CSR: Less favorable for SEO as the HTML content is initially empty.
• SSR: More favorable for SEO as the HTML content is fully-formed when received, ensuring better indexing.

Use Cases

• Use CSR for:
  • Admin dashboards, accounting applications, music players, file converters.
  • Applications not dependent on SEO and require fast in-app navigation.
• Use SSR for:
  • Blogs, social media sites, e-commerce platforms, personal portfolios.
  • Applications that benefit from good SEO and where content discoverability is crucial.

Conclusion

• Choose CSR or SSR based on the specific needs of your application.
• CSR offers better client-side navigation speed and is suitable for app-like websites.
• SSR provides faster initial load and better SEO performance, essential for content-heavy and searchable sites.

Feel free to ask questions anytime!