In today’s digital world, speed and smooth performance are as important as design. A modern web app must load quickly and respond without delays. If it feels slow, users leave within seconds. This is why performance is now as critical as visuals.
The Ext JS Toolkit makes building fast and feature-rich apps easier. It comes with ready-to-use UI components such as grids, forms, menus, and charts. These components are built to be reliable, secure, and consistent across devices. When combined with ExtJs themes, they also look polished and professional.
But there’s always room for improvement. By following a few simple best practices, you can boost the performance of your Ext JS UI components and deliver a seamless user experience. Let’s explore them step by step.
Why UI Performance Matters
A good-looking app is not enough. The app must also be responsive. Users expect instant results when they click, scroll, or search. If your app is delayed, they lose patience and may never return.
Poor performance not only frustrates users but also affects your visibility on search engines. Google ranks faster apps higher. This means a sluggish interface could harm your SEO.
Ext JS helps developers avoid such problems with its Ext JS pre-built components. But for the best results, you must still look for bottlenecks and fix them early.
Finding Performance Bottlenecks in Ext JS Apps
Before you optimize, you must first identify what is slowing down the app. There are a few ways to do this.
Profiling tools are a good starting point. Chrome DevTools and Firefox Developer Tools also let you track CPU, memory, and JavaScript execution.
Network monitoring tools like GTmetrix and WebPageTest can show how long different resources take to load. They help you spot slow images, scripts, or components.
You can also check page loading speed with Google PageSpeed Insights. It points out which elements reduce performance.
Lastly, run cross-browser testing. Even though Ext JS components are designed for all major browsers, small differences can appear. Testing ensures your app runs well everywhere.
Best Practices to Improve Ext JS UI Component Performance
1. Optimize DOM Manipulation
The DOM (Document Object Model) is what browsers use to display apps. If you update it too often or make it too heavy, performance suffers.
With Ext JS, you don’t need to work directly with DOM elements. The Ext JS Toolkit has pre-designed components like forms, grids, and menus. These are already optimized for performance.
2. Data Loading and Rendering Optimization
Large datasets often slow down apps. When a grid or list tries to load thousands of records at once, the UI freezes. Ext JS solves this problem with smart data handling features.
Data buffering (virtual scrolling) ensures that only a small portion of records shows at one time. More data loads only when needed.
Pagination splits large datasets into smaller pages. Instead of rendering everything, the app handles one page at a time.
Finally, Ext JS stores manage and organize data. They make filtering, sorting, and binding efficient across multiple components. By using stores properly, you avoid unnecessary load on your UI.
3. Implement Code Splitting
If your app is large, loading everything at once will make it slow. Code splitting fixes this problem by breaking the code into smaller pieces.
With Cmd, you can create optimized bundles. The app then loads only what is needed at the start. Other modules load later, when users actually use them.
This means the first screen loads quickly, and users don’t wait for features they may never use. Code splitting is especially useful for enterprise apps with multiple modules.
4. Use Lazy Loading and Deferred Rendering
Lazy loading ensures components load only when the user opens them. For example, a settings panel doesn’t need to load at startup. It can load later, on demand.
Deferred rendering delays rendering until a component is visible. If a tab or section is hidden, it won’t render until opened.
Both methods reduce memory use and speed up startup. Together, they give users a smoother experience right from the first click.
5. Cache and Reuse Components
Creating new UI components again and again wastes resources. Instead, you can cache components and reuse them when needed.
For example, if your app uses the same grid in multiple places, reusing it saves memory. Caching also makes heavy components load faster, since they don’t need to be built from scratch every time.
This practice is simple but powerful. It reduces memory use, shortens load times, and makes your UI feel much more responsive.
Conclusion
The performance of your web app plays a major role in user satisfaction, SEO, and long-term success. While the Ext JS Toolkit already provides powerful UI components, developers can take performance to the next level by applying the right strategies.
To summarize:
- Optimize DOM manipulation with component-based architecture.
- Improve data handling with buffering, pagination, and stores.
- Use code splitting to reduce initial load times.
- Apply lazy loading and deferred rendering for smoother experiences.
- Cache and reuse components to save resources.
By following these five best practices, your Ext JS applications will be faster, more responsive, and more user-friendly. Extnuke by Imbibe Tech creates modern, professional ExtJs themes that enhance the look and performance of your apps. Our themes are built to complement the Ext JS Toolkit, ensuring your applications are both attractive and highly optimized. If you want to improve the speed and design of your Ext JS projects, explore our collection of themes today.