React Server Components

By Pieti Kinnunen

September 17th, 2025

What Are React Server Components?

In modern web development, the need for both efficient rendering and interactivity has led to the evolution of several rendering strategies. Here's a breakdown of the main rendering paradigms:

• Server-Side Rendering (SSR): The server generates the HTML file at either request time or build time and sends it to the client. The client then "hydrates" this HTML by adding any necessary interactivity.

• Client-Side Rendering (CSR): The client loads an empty HTML file and then fetches data to populate the content dynamically. This often requires multiple database queries after the HTML is delivered, leading to additional network requests.

React introduced a new paradigm, React Server Components (RSC). React Server Components were first adopted by Next.js and they bring together the best of both worlds. Server components allow as much of the HTML to be rendered on the server as possible, sending that pre-rendered content to the client while leaving any interactivity to be handled on the client side. Essentially, the server generates the component, performs necessary data fetching like database queries, and sends the fully rendered HTML, including the external data, to the client. The client can then handle any required interactivity without needing to re-render the entire page.

Why Should You Care About React Server Components?

React Server Components address several common performance challenges in modern web applications. Here's why you should consider using them:

1. Reduced JavaScript Bundles
   With Server Components, much of the page content is rendered on the server. This means the client doesn’t have to download heavy JavaScript libraries to render static content. For example, instead of sending the entire markdown rendering library to the client, only the pre-rendered HTML is sent. This significantly reduces the size of the JavaScript bundle and makes the app faster to load.

2. Improved Performance
   By shifting the rendering workload to the server, the amount of JavaScript that needs to be downloaded and executed by the browser is drastically reduced. This results in faster load times and a more responsive user experience, especially for users with slower internet connections or less powerful devices.

3. Better SEO
   Since the server pre-renders the content, search engine crawlers can easily access the fully-rendered HTML. This leads to better SEO performance, as the content is immediately available for indexing. In contrast, client-side rendering (CSR) often makes content inaccessible to crawlers until the JavaScript has been executed, which can negatively impact SEO.

4. More Efficient Data Fetching
   RSC allows for server-side data fetching, which means data is retrieved directly from the database or APIs on the server before sending the content to the client. This eliminates the "waterfall" effect, where multiple client-side requests slow down page load times. It can also make development more straight-forward. Since the data that each component needs can be fetched directly in the component itself, debugging potential issues can be more simple. Having each component fetch its own data can also make caching more efficient. When data for one component is updated, all the others can still keep their cached data and the application can just re-fetch the and revalidate the data for that one component without the need to execute all queries for a given page again or having to rebuild the entire site. 

5. Enhanced Security
   Fetching the data on the server means that sensitive data, like API keys or tokens, can remain on the server, reducing security risks by preventing exposure to the client. You can query data directly in the components without the need to configure separate APIs while still keeping the requests secure.

How React Server Components Work

React Server Components work by splitting rendering between the client and server:

• Server-Side Rendering: The content is rendered on the server and sent to the client. This is ideal for static content, like blog posts or product pages, where content doesn't need to change dynamically.

• Client-Side Rendering: For interactive components (like a live chat or an image gallery), React can use client-side rendering to handle user interactions after the initial page load.

By combining SSR and CSR, RSC allow developers to minimize the amount of JavaScript the client needs to download, leading to faster load times and better performance overall.

React Server Components can also be used in a hybrid model with “use client”, allowing you to define components that should be rendered on the client. This allows you to use stateful methods and browser-dependent features such as browser cookies or local storage, while keeping server specific components performant and secure.

RSC can be run once at build time to fetch content or they can be combined with a web server and they can fetch the data at run time. This way data can be cached and invalidated when needed without the need to rebuild your application. Server components can be used in a static website without a web server if they only fetch their data at build time.

Key Benefits of React Server Components

• Faster Page Loads: By rendering HTML on the server, React Server Components allow pages to load faster, as clients don’t have to wait for JavaScript to render the page.

• Smaller Bundle Sizes: With less JavaScript to send, bundle sizes are smaller which can significantly reduce load times.

• Simplified Architecture: Developers can build components that run solely on the server, which simplifies the app architecture by reducing the need for complex client-side logic and state management.

• Better Caching: Since Server Components are pre-rendered on the server, they can be cached effectively, reducing server load and further improving speed.

• Improved Developer Experience: RSC abstracts away many of the complexities of client-side rendering, allowing developers to focus on building more efficient, server-centric apps. They can take advantage of simple request/response workflows while still maintaining seamless interactivity for users.

React Server Components with Next.js

While React Server Components are an exciting new feature, they are most commonly associated with Next.js, one of the most popular frameworks built on top of React. Next.js was the first React framework to implement RSC, which it did in late 2022 with the announcement of their new App router. Back then, RSC weren’t officially stable. They became stable with the release of React 19 in late 2024 so other frameworks, such as Gatsby, have only recently enabled the use of RSC in their frameworks. Next.js leverages React Server Components to bring a hybrid SSR + CSR model that optimizes performance and SEO. By combining the power of React with the server-side capabilities of Next.js, you can get a great user experience with minimal JavaScript and fast load times.

How Next.js implements RSC:

• SSR with Static Export: Next.js allows you to statically export pages that are pre-rendered on the server, which are then served as static HTML to the client. This improves performance and SEO because search engines can index the pre-rendered content right away.

• Dynamic React Server Components: These can be used dynamically, allowing React to re-fetch and re-render components from the server when needed, for instance when new data is available.

Are React Server Components Available in Other Frameworks?

While React Server Components are a relatively new concept, they are currently tightly integrated with Next.js. However, there is growing interest in bringing similar capabilities to other React-based frameworks. The community is actively exploring the integration of RSC in different environments, and it's likely that future releases of other popular frameworks (like Remix or Gatsby) will adopt similar strategies for optimizing server and client-side rendering.

Conclusion

React Server Components are a powerful tool for optimizing web applications by improving performance, reducing client-side JavaScript, and providing better SEO. With the ability to pre-render components on the server and minimize unnecessary re-renders, RSC enables faster load times, improved security, and an overall smoother user experience. While Next.js is currently the most popular framework to use with React Server Components, other frameworks will likely adopt similar patterns as the demand for server-side rendering and hybrid models continues to grow.