Learn how to use Angular’s defer block to improve performance

By Fanis Prodromou | #12 Angular Meetup

Angular is a popular frontend framework that is widely used for building web applications. One of the key factors in the performance of an Angular application is how efficiently it loads and renders the content. In this article, we will explore the use of Angular’s defer block to improve the performance of your application.

What is the defer block?

The defer block in Angular is a way to delay the loading and execution of certain scripts until after the page has been fully parsed. This can be helpful in improving the initial load time of your application, as it allows the browser to continue parsing and loading the rest of the page without being interrupted by script execution.

How to use the defer block

To use the defer block in Angular, simply add the defer attribute to the script tag that includes the script you want to defer. For example:

        
          <script src="app.js" defer></script>
        
      

By adding the defer attribute, the app.js script will be deferred until after the page has been fully parsed. This can significantly improve the initial load time of your application, especially if you have large scripts that take a long time to execute.

Benefits of using the defer block

Using the defer block in Angular can provide several benefits, including:

• Improved initial load time: By deferring the loading and execution of certain scripts, you can improve the initial load time of your application, providing a better user experience.
• Reduced script execution interruptions: By allowing the browser to continue parsing and loading the rest of the page without interruption, the defer block can help reduce script execution interruptions, leading to smoother and faster page rendering.
• Better performance on slower devices: Deferring script loading and execution can also improve the performance of your application on slower devices with limited processing power.

Conclusion

By using Angular’s defer block, you can improve the performance of your application by optimizing the initial load time and reducing script execution interruptions. This can lead to a better user experience and improved performance on a wide range of devices. If you’re looking to optimize your Angular application, consider using the defer block to improve performance.