Many studies and researches have proven one thing and that is performance matters. These studies validate the claims that the slow performance of your web app frontends impact greatly on your ability to acquire and retain new users. New visitors won’t bother coming back on your web applications if they don’t get the blazing fast performance.

The performance of the frontend is a crucial part of building a whole new web app. I have already talked about the most preferred frontend frameworks and what frameworks to choose from in my past blogs. Today, I’ll be talking about frontend performance optimization patterns and where and how to effectively utilize them and implement them to boost performance.

So, without further ado, let’s get started with the frontend performance patterns that help you boost the performance of your web app.

Frontend Performance Patterns to Boost Performance for Your Web Frontend

Client-Side Vs Server-Side Rendering

Client-Side Rendering often abbreviated CSR is a rendering pattern that puts the entire work of rendering JavaScript on the users’ browsers. It is simple and easy to implement and works best for small-scale applications as it can load frontends faster.

But as the size of the web app increases, so does its JavaScript bundle. Thus, the workload on browsers increases as well to download the bigger JavaScript bundle pack and fetch data in order to render a frontend page completely. The initial speed of rendering a web page is often slow, but with the help of caching mechanism in place, it can be improved for later interactions.

Server-Side Rendering (SSR) is most of the time faster than CSR as the entire load isn’t only with the users’ browser. I have already written a detailed guide on server-side rendering before. Let me explain the concept once again. First, the server will fetch and render the HTML version of the page for users to see until the browser downloads the JS files to make it interactive.

Since the computing powers of server available nowadays is pretty good, SSR is quite the zeal and is a faster frontend performance pattern. Still, there is another rendering performance pattern in the background catching up recently. It is Static-Site Generation.

Static Site Generation Performance Pattern

Static Site Generation (SSG) is the fastest of all the rendering methods that recently went mainstream. The concept behind SSG is it does all the work of data fetching and HTML rendering at the build time. These pre-built HTML pages are deployed by the web servers from where browsers make a request and are provided a lightweight HTML page version. The rendering cycle takes only milliseconds, which is blazing fast and aids in SEO too.

However, due to the dynamic or frequently update nature of modern web apps, Static Site Generation isn’t widely being practiced. Also, the implementation of the same isn’t exactly piece of cake for developers. But there’s still a way around and let’s see what it is.

Using SSG with Stale-While-Revalidate (SWR) Pattern

Since we learned that SSG is by far the fastest rendering method for frontend performance, the only catch was that the pattern is not suitable for dynamic aspects. Applications with authentication protection or frequent data updates can’t be handled at the build-time because there’s JavaScript to consider.

What can be done here is a static version of the page should be served first, then JavaScript files can be fetched for any changing data. For the same, stale-while-revalidate pattern can be used to serve static version and updated from cache (stale). Then to revalidate, fetch request is sent with updated UI, which enables SSG to provide fast and reactive UI consistently.

Overall, the process becomes efficient and provides stellar performance and experience for users rather than serving a blank page. Seeing its potential, many modern web development frameworks such as Next.js have adopted and do an excellent job of implementing this frontend performance pattern.

Optimizing the Static Media Assets

There are two static assets code files and media files. Images and video are data-heavy and poorly optimized, thus need to be optimized for higher performance. What you can do is compress your images or use WebP image format to serve responsive images and not the data-heavy media files.

Further, you can go for a Content Delivery Network or a Serverless Image Handler to serve responsive images to users. Such solutions offer to serve and manipulate the image sizes based on the varying device widths rather than storing different sized images. They are powerful and high performant tools to server media-heavy static assets.

As for the code files, minify and compress the code files to as small sizes as possible and serve them from a CDN.

Prefetching, Lazy Loading, and Caching

Prefetching is where a resource is loaded even before it is required to reduce the time taken to fetch that piece of content when actually needed. The developer teams can tell browsers to fetch any resource when the page is loaded before the user makes a request.

Lazy loading is a powerful frontend performance pattern where only the required portion is loaded and the remaining part is delayed until users need it. Most social media apps today have lazy loading in-built.

Caching is another performance booster pattern for web frontends. Caching enables stacks to do less work for most common requests or distribute workload effectively that can’t be eliminated.

Wrapping Up

So, let’s wrap up on the frontend performance patterns. This guide equips you with the powerful knowledge of different types of rendering that boost performance of your web applications. I have provided some important performance patterns, others you might already know. Regardless, each pattern is implemented individually or combined with others to improve the performance of your application’s frontend.