Server-Side Rendering in ReactJS: Benefits and Implementation


Server-Side Rendering (SSR) is a popular technique in modern web development, especially when working with libraries such as ReactJS. SSR involves generating the HTML of a page on the server rather than in the browser. SSR sends a fully rendered page to the client; the client’s JavaScript bundle takes over and enables the page to be reactive.

Benefits of Server-Side Rendering

There are several compelling advantages to using SSR in your React applications.

Improved performance

With SSR, your users can start viewing your web page while the rest of the content continues to load. This is particularly beneficial for users with slow internet connections.

SEO Improvement

Search engines have an easier time indexing server-rendered content. This is crucial for public-facing web pages needing a high organic search ranking.

Better User Experience

SSR alleviates the “white screen of delay” issue in client-side rendering by sending a fully rendered page to the client.

Challenges of Server-Side Rendering

While the benefits of SSR are evident, it’s important to note that it also comes with its own set of challenges.

Increased Server Load

Since the server is responsible for rendering the HTML pages and sending them to the client, it can cause a high load on the server, impacting performance. This requires robust server optimization and potentially higher server costs.


Implementing SSR can be complex, particularly when managing state or dealing with frameworks that are not designed with SSR in mind. This can lead to additional development overhead.

Time to Interactive

Although SSR can improve the perceived load time, it can also delay the time to interactive (TTI), the point at which users can start interacting with the app on their screen. This is because the JavaScript still has to be downloaded and parsed on the client side.

Implementing SSR in ReactJS: A Closer Look at the Challenges

While ReactJS is a robust library for building user interfaces, implementing SSR in ReactJS can often be a daunting task.

Routing and data fetching

ReactJS doesn’t provide any built-in support to handle routing and data fetching on the server side. Developers have to rely on third-party libraries, and the implementation can get complex, especially for large-scale applications.

Managing Component Lifecycle

Server-rendering in ReactJS skips lifecycle methods such as `componentDidMount` and `componentDidUpdate`. This can lead to bugs and issues if these lifecycle methods are crucial in your application.


In server-rendered ReactJS applications, the server has to deal with tasks such as code splitting, bundling, and serving the right chunks to the right places. This might require additional tooling and configuration to optimize.

Bundle size

With SSR, the same code runs on both server and client. This can increase the JavaScript bundle size, affecting the application’s performance. Remember, though, while these challenges may seem daunting, they can be overcome with careful planning, robust architecture, and the right tools.

Strategies for Optimizing SSR in ReactJS

Optimizing Server Side Rendering (SSR) in ReactJS requires careful planning and implementation. Here are key strategies that can help mitigate the challenges associated with SSR:

Third-Party Libraries

Make use of third-party libraries such as Redux or MobX for managing application state, and Next.js or After.js for routing and SSR. These can simplify complex processes and reduce the amount of custom code needed.

Code Splitting and Lazy Loading

Implement code splitting using libraries such as Loadable Components to split your JavaScript bundle into smaller chunks. Complement this with lazy loading to serve only the necessary code, reducing the initial load time.

Optimize Component Lifecycle

Carefully manage your component lifecycle methods. Use the `componentDidMount` method for client-side only actions and the `constructor` or `componentWillMount` methods for code that can be executed on both server and client side.

Server Caching

To reduce the load on your server, implement caching strategies. This can drastically reduce the time to serve the pre-rendered page, improving the overall performance of your application.

Reduce Bundle Size

Use tree shaking and dead code elimination techniques to reduce your bundle size. This can be achieved using tools such as Webpack or Rollup.

Monitor and Analyze Bundle

Use tools like Webpack Bundle Analyzer to visualize the size of webpack output files. This can assist in understanding how code is bundled and identifying areas for optimization.

Server-Side Rendering (SSR) can have a significant impact on the performance of a web application. Firstly, SSR can improve the initial load time of your ReactJS web development. As the HTML content is generated on the server and sent to the browser, the user can start viewing the page while the rest of the application’s JavaScript is still loading. This can lead to a better user experience, particularly on slow networks.

Secondly, SSR can be beneficial for SEO as search engine crawlers can index server-rendered content fully and faster. However, it’s worth noting that SSR can also lead to higher server load. Since the server has to generate a new HTML page for every request, applications with high traffic might see increased CPU usage. This is where strategies like server caching come into play, which can help in efficiently managing high server loads. Overall, the impact of SSR on performance can be both positive and negative, and it largely depends on how effectively it’s implemented and managed.


In conclusion, server-side rendering (SSR) is a valuable tool in a developer’s kit, especially when it comes to improving the performance of a web application. It not only enhances the initial load time but also optimizes SEO, making content more accessible to search engine crawlers. However, its implementation should be done judiciously, keeping in mind the potential increased server load. By utilizing the right tools and strategies, like tree shaking, dead code elimination, bundle analysis, and server caching, developers can significantly optimize web application performance. It is this thoughtful application and management of SSR that determines its overall impact on your web application’s performance and user experience.