Client-side vs. server-side rendering

Faster webpage load times play a huge role in user experience and SEO, with page load speed being a crucial factor in Google’s algorithm.

A front-end web developer must decide how best to render a website so that it offers a fast experience and dynamic content.

Two popular rendering methods are client-side rendering (CSR) and server-side rendering (SSR).

All websites have different requirements. So, by understanding the difference between client-side and server-side rendering, you can render your website in a way that meets your business goals.

What is client-side rendering and how does it work?

Client-side rendering is a relatively new approach to rendering websites.

It became popular when JavaScript libraries started incorporating it, with Angular and React.js being some of the best examples of libraries used in this type of rendering.

It works by rendering a website’s JavaScript in your browser and not on the server.

The server responds with a plain HTML document containing the JS files instead of fetching all the content from the HTML document.

While the initial upload time is a bit slow, subsequent page loads will be fast since they don’t rely on a different HTML page per route.

From managing logic to getting data from an API, client-rendered websites do everything “independently”. The page is available after the code runs because each page that the user visits and its URL are dynamically created.

The CSR process looks like this:

  • The user enters the URL they want to visit in the address bar.
  • A data request is sent to the server at the specified URL.
  • On the client’s first request for the site, the server delivers the static files (CSS and HTML) to the client’s browser.
  • The client browser downloads the HTML content first, followed by JavaScript. These HTML files connect the JavaScript and start the loading process by showing the user developer-defined loading symbols. At this point, the website is not yet visible to the user.
  • After the JavaScript is downloaded, the content is dynamically generated in the client’s browser.
  • The web content becomes visible as the client navigates and interacts with the website.

What is server-side rendering and how does it work?

Server-side rendering is the more common technique for displaying information on a screen.

The web browser sends a request for information from the server, retrieves user-specific data for padding, and sends a fully rendered HTML page to the client. Each time the user visits a new page on the website, the server repeats the entire process.

This is how the SSR process works step by step:

  • The user enters the URL they want to visit in the address bar.
  • The server provides the browser with a fully rendered HTML response.
  • The browser renders the page (now visible) and downloads JavaScript.
  • The browser runs React, making the page interactive.

What are the differences between client-side and server-side rendering?

The main difference between these two rendering approaches lies in the algorithms of their operation. CSR shows a blank page before loading, while SSR shows a fully rendered HTML page when it first loads.

This gives server-side rendering a speed advantage over client-side rendering because the browser doesn’t have to process large JavaScript files. Content is often visible within a few milliseconds.

Search engines can crawl the website for better SEO, making it easy to index your web pages. This readability in the form of text corresponds exactly to the way SSR sites are viewed in the browser.

However, client-side rendering is a cheaper option for website owners.

It offloads your servers and hands off the responsibility of rendering to the client (the bot or user trying to display your page). It also offers rich website interactions by providing fast website interaction after initial loading.

Fewer HTTP requests are made to the server with CSR, unlike in SSR, where each page is rendered from scratch, resulting in a slower transition between pages.

SSR can also buckle under a high server load if the server receives many simultaneous requests from different users.

The drawbacks of CSR are the longer initial loading time. This can impact SEO; crawlers might not wait for the content to load and exit the site.

This two-phased approach raises the possibility of seeing empty content on your page by missing JavaScript content after first crawling and indexing the HTML of a page. Remember that, in most cases, CSR requires an external library.

When To Use Server-Side Rendering

If you want to improve your Google visibility and rank high in the search engine results pages (SERPs), server-side rendering is the number one choice.

E-learning websites, online marketplaces, and applications with a straightforward user interface with fewer pages, features, and dynamic data all benefit from this type of rendering.

When To Use Client-Side Rendering

Client-side rendering is usually paired with dynamic web apps like social networks or online messengers. This is because these apps’ information constantly changes and must deal with large and dynamic data to perform fast updates to meet user demand.

The focus here is on a rich site with many users, prioritizing the user experience over SEO.

Which Is Better: Server-Side Or Client-Side Rendering?

If your site’s content doesn’t require much user interaction, then SSR is more effective. It positively influences accessibility, page load times, SEO, and social media support.

On the other hand, CSR is excellent for providing cost-effective rendering for web applications, and it’s easier to build and maintain; it’s better for First Input Delay (FID).

Sometimes, you don’t have to choose between the two as hybrid solutions are available. Both SSR and CSR can be implemented within a single website or webpage.

For example, in an online marketplace, pages with product descriptions can be rendered on the server, as they are static and need to be easily indexed by search engines.

Pages like user accounts don’t need to be ranked in the SERPs, so a CRS approach might be better for UX.

Both CSR and SSR are popular approaches to rendering websites. You and your team need to make this decision at the initial stage of product development.

Think about your project and how your chosen rendering will impact your position in the SERPs and your website’s user experience.

Generally, CSR is better for dynamic websites, while SSR is best suited for static websites.

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