Disadvantages of SSR

#1. Increased server load

• On every request the server has to:
  • execute the application code,
  • gather the data,
  • render the HTML.
• Unlike CSR, where the server just serves a static file, SSR requires far more resources.

Consequence: for high-load projects, the SSR server can become a bottleneck and require scaling.

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#2. Higher latency (TTFB)

• With SSR, the server has to run the logic and rendering before it can respond.
• With CSR, the server immediately returns an empty HTML shell and JS bundles, so the time to first byte (TTFB) is usually lower.

Consequence: although the first content appears quickly, the server response time is higher, especially for complex pages.

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#3. Architectural and infrastructure complexity

• An SSR application requires:
  • a dedicated server environment (Node.js),
  • configuring routing, caching, and load balancing,
  • carefully synchronizing state between the server and the client ("hydration").

Consequence: DevOps setup and CI/CD become more complex than for a plain SPA.

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#4. Duplicated code and data logic

• You need to write code that works both on the server and on the client (universal / isomorphic JS).
• For example, when loading data in Next.js via getServerSideProps, you have to think about how to avoid duplicating API requests during hydration.

Consequence: more points of failure, harder to debug and maintain.

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#5. Slower navigation between pages (without SPA optimizations)

• If client-side routing isn't implemented (the way Next.js does it), then every navigation between pages triggers a new server request → the whole page repaints.

Consequence: without optimizations, the UX can feel "heavier" than a CSR SPA.

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#6. Harder to cache the result

• With CSR, static assets can be cached on a CDN.
• With SSR, the HTML response is dynamic, and it's not always safe to cache (especially with personalization).

Consequence: higher load, harder to control performance.

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#7. Potential hydration issues

• After the page loads, the client-side JS has to "connect" to the server-rendered HTML (hydration).
• If the DOM structure differs between the server and the client, errors appear such as "Hydration failed because the initial UI does not match what was rendered on the server".

Consequence: requires careful synchronization of state and render logic.

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#8. Environment limitations

• Server-side rendering runs in Node.js, not in a browser:

  • you can't use window, document, localStorage, etc.

  • you have to write conditional checks:

    javascript

    Copy

    if (typeof window !== 'undefined') { ... }

Consequence: more conditional code and potential bugs.

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#Summary comparison