Server-side rendering in React: benefits, challenges, peculiarities 

React is a widely utilised JavaScript library which helps construct responsive and engaging user interfaces. Default operation mode implies rendering on the client’s side, and so the system loads within the user browser. Thus, HTML content is being dynamically produced by React components. However, for some purposes, including SEO, React server-side rendering can be especially beneficial. What does server-side rendering mean? – We will answer the question in this post and dwell on the specifics of rendering, as well as the benefits and possible drawbacks of the approach. 

Server-side rendering (SSR) is grounded in rendering React elements within the server before transmitting full HTML markup to users. If your goal is to develop applications with server-side rendering functions, think of adopting Next.js –  one of the most popular React UI frameworks. 

React server-side rendering: how does it operate?

Simply put, this is an overview of how server-side rendering functions:

1. When users send the initial request to load pages, the React rendering code is run by the system. Then, the HTML markup is being generated. 
2. The user receives the entirely rendered HTML from the server.
3. React hydrates the static HTML by bootstrapping the client-side application. The system attaches event handlers, and the page gains interactive functions. 
4. Subsequent navigation operates through component rendering and client-side routing. 

The user request usually takes a few milliseconds; however, your server’s location, internet connection speed, and degree of website optimisation may affect the speed of request processing. So, if your priority is prompt request processing, you should thoroughly analyse all factors that accelerate the speed of processing. 

To encapsulate, SSR helps the first page of your application to become more SEO-friendly and increases the speed of load. After the first load, the system provides users with a seamless SPA – Single Page Application experience.

We will also highlight e-commerce use cases of server-side rendering for a better understanding of the specifics of SSR. 

E-commerce solutions are known for their dynamicity: such systems require constant updates on pricing, special offers and the latest inventory options. E-commerce platforms need to be accessible to clients and search engines and rapidly indexed. SSR contributes to the pages’ responsiveness by generating each page’s HTML on the server. 

Why do you need to create react app server-side rendering? Primary benefits of the approach.

1. Faster load of initial pages. SSR assists in getting rid of extra roundtrips for fetching JSON data and JavaScript. Rendering HTML fully on the server results in an enhanced user experience. 
2. Consistency of the first paint. Faster HTML rendering contributes to the consistency of first-paint timings across your pages. 
3. Operates without JavaScript. SSR enables the page to operate without utilising client-side JavaScript. 
4. Possibilities of integration with server-side code. Developers can take advantage of existing backend code in Ruby or Python to render necessary components. 
5. Strengthened security. SSR is also beneficial for various cyberthreat prevention methods, including XSS – Cross-site Scripting Attacks: the approach decreases the need for dynamic execution of JavaScript on the client side. 
6. Better (TTI) – Time-to-Interactive. Not only does server-side rendering help obtain faster initial load, but it also provides users with more prompt TTI. This is because the HTML file sent by the server has already been hydrated with data and event listeners. 

Alongside the aforementioned advantages, SSR allows websites to reap several other benefits related to SEO and overall performance. Here, we list only a few of the most important ones. 

These are additional benefits of server-side rendering for SEO and performance. 

1. Since search engine crawlers parse static HTML files that are rendered within the server, improved indexation of content is obtained. 
2. Your platform obtains higher visibility and search engine rankings. 
3. A possibility of leveraging CDN catching of the rendered HTML. 
4. As HTML hydrates faster, this decreases time-to-interactive. 

What are the possible challenges of SSR in React?

Despite the numerous benefits of server-side rendering, it is essential for developers to know how to overcome several challenges along the way in implementing SSR. Here, we consider the most common questions you will need to address within the framework. 

1. More complex setup. Since SSR presupposes configuring the server for rendering in addition to the client application, it inevitably complicates the setup. 
2. Vendor libraries. Keep in mind that third-party libraries may require specific actions to prepare them to work with SSR. They, for instance, may need workarounds and be dependent on browser APIs. 
3. Repeated logic. Some code entities run both on the client side and the server: you need to follow the same logic of data loading in two places. 
4. Server load. Consuming significant CRU and memory resources is sometimes indispensable for rendering on the server. To prevent system overload, these processes need to be optimised wisely. 
5. Session management. Session stores and cookies have to be synced on the server and client sides. 
6. Mismatches of data. After client-side rendering, some data mismatches may arise if your data on the server is stale. 
7. Debugging. Bugs may only appear on the client or server side, which makes debugging more complex. 
8. Caching. For repeated request prevention, an accurate catching needs to be applied, 
9. Streaming. Usually, server-streamed responses are more complex when handled on the client side. 

When to use server-side rendering? And how do you optimise the performance of the system?

To take full advantage of SS, it is worthwhile to study special techniques that enable you to improve your performance significantly.

• Code splitting 

This approach is grounded in separating the code of your app into smaller components, which leads to decreasing initial load time. While working with SSR, you may apply the technique to make sure that only useful code units are loaded on your server. In such a way, you attain improved perceived performance and time-to-first-paint. Code-splitting techniques in React comprise dynamic and static imports. The former helps request only necessary code units, while the latter allows for loading code in times of the initial SSR render. 

• Server-side caching and client-side caching

Caching is an indispensable practice for decreasing the number of clients’ requests, thereby reducing server load and benefiting performance. Server-side caching techniques encompass file caching, database caching, and memory caching. Each of them can be fruitfully combined with code splitting. Another effective technique is client-side caching – you can implement it by applying built-in React hooks (useReducer, useContext). Alternatively, you may also utilise third-party libraries (Redux) for these purposes. This sum of approaches brings significant enhancements to user experience.

• Minimising network requests

Minimising network requests is no less important for reducing user frustration. One efficient strategy for that is bundling all necessary assets (JavaScript files or CSS) into a single response. Similarly to previous practices, this step contributes to decreasing the load time. 

Wrapping up

Undoubtedly, SSR using React encompasses a variety of advantages, especially if you want to develop dynamic and powerful web apps or solutions with heavy backends.  Better experiences for people with relatively slow devices or limitations in processing power are overriding points for implementing SSR. In addition, the technology enables companies to achieve consistency of UI across different browsers. 

Even though server-side rendering implies some challenges, namely maintenance specifics and complex setup, cutting-edge frameworks (Next.js and Express.js) optimise the adoption of SSR. Along the way, it is also worthwhile to consider an efficient caching strategy and get yourself covered by robust infrastructure support. We hope this post has shed light on the “what is SSR” question, as well as on possible ways of maximising the benefits of SSR. 

If you need to hire a reliable and experienced team to implement React for your project’s needs, don’t hesitate to contact the PNN Soft team. We have more than 20 years of experience in elevating existing solutions for businesses and creating innovative systems for levelling up your company’s operations.