What’s the meaning of client side and server side?
In this article, we'll explore the meaning of Client Side Rendering (CSR) and Server Side Rendering (SSR). We'll explain the key differences between client and server roles in web development, how rendering works on both sides, and how each approach impacts performance.
Client vs. server: what’s the difference?
When building a website or application, it’s more important to make a decision between client or server side rendering. This decision can impact user performance and SEO. Let’s take a look at how each one works.
Client side rendering
With client side rendering, the server sends HTML, CSS and JavaScript to the browser. The browser then dynamically generates the content to be rendered in the DOM for the visitor.
Server side rendering
In server side rendering, the server does the heavy lifting. The server generates the complete HTML for a page before sending the rendered page to the browser. The browser is then able to display the content upon arrival.
Server side rendering vs. client side rendering
Choosing between server side rendering and client side rendering depends on a few key factors. The first consideration when making this decision should be the type of website in question.
If your website doesn’t require frequent updates, then SSR is typically the better option. Websites such as news sites and blogs benefit from fast initial load times, with a focus on delivering static content rather than interactivity. Since the content is mostly static, the pages will rarely need to be updated after delivery to the visitor. SSR may feel faster on the first load but can be slower to become interactive.
Not only is this a better experience for the user, but the website benefits with an advantage in SEO. As server side rendering makes content easily discoverable for search engine crawlers. This is because the HTML is fully rendered and sent from the server.
On the other hand, CSR is ideal for interactive or dynamic websites. Best suited websites are where the content updates based on user actions, such as a SAAS platform. CSR allows for smoother user experiences, faster page transitions, and dynamic content fetching without full page reloads.
Since the content is generated dynamically in the browser, it can be harder for bots to access, which may limit SEO visibility.
CSR is often better suited for applications that use basic authentication or rely heavily on client side state and interactions, such as dashboards.
SSR vs. CSR for performance
Both SSR and CSR have strengths and trade-offs that affect initial load times, interactivity, and overall user experience. Let’s take a look at some key performance differences.
Initial Load Time
SSR delivers fully rendered HTML from the server, making the first page load significantly faster. This allows users to view content quicker, even before JavaScript finishes loading and executing.
With CSR, the browser needs to render the page, resulting in a noticeable difference in initial load times compared to SSR. This slow initial load time can particularly be an issue on slower devices or networks.
Interactivity
CSR has a massive advantage in interactivity. Since all rendering logic runs in the browser, user interactions can happen faster. Components are handled dynamically without requiring a full page reload. This is ideal for applications such as dashboards, where responsiveness is key.
To mitigate delays in SSR, developers often use skeleton screens or loading components. These give users visual feedback while the server prepares and sends the fully rendered HTML, helping to bridge the gap between request and full content delivery.
JavaScript Dependency
CSR heavily depends on JavaScript for rendering. If JavaScript is disabled, some or all of the page content may fail to display. SSR ensures that essential content is still accessible even without JavaScript.
Server Load
SSR can increase the load on the server, especially for dynamic websites that must render content on every request. As mentioned previously, SSR pages typically require full reloads to reflect changes, which can negatively affect user experience when traversing the website. As new requests the server must reprocess and re-render content.
Conclusion
Monitoring performance is important for both client side and server side rendering.
We mentioned earlier in the article how SEO is impacted depending on how pages are rendered. Having good Core Web Vitals can also impact SEO, as Google ranks better performing websites in their search results.
With DebugBear, you can monitor your website over time. Catching regressions as they happen.
If you have a client side rendering website, you can test and monitor how pages perform once a user logs in with Login Flows.
DebugBear is a page speed testing tool that helps you keep track of your website performance in the lab and with real-user analytics.
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Monitor Page Speed & Core Web Vitals
DebugBear monitoring includes:
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