Your Conclusive Guide to Angular Performance Optimization in 2023

Are you looking for a quick checklist to optimize the performance of the Angular app? This blog will help you dive deep into the process of Angular performance optimization;

Introduction

Angular is a highly used framework for creating web and mobile applications.

Therefore, to deliver a seamless application, it’s vital to optimize and improve the performance of Angular. 

What if your Angular app is loaded twice as fast?  

If you want to double or triple the performance of your Angular app and don’t know ways to optimize and improve the runtime, we’ve got you covered. 

And whenever someone asks you to know your Angular app is slow, you know where to look and what issues to resolve. Isn’t this what you are looking for?

Here’s a guide you can refer to optimize the performance of your angular app;

Measuring and Profiling the Performance of Angular Application

Calculating the loading time is the first step toward improving the Angular app’s performance.

Some dedicated angular developers know they need to optimize their apps but don’t know exactly where to begin. They try to shoot in the dark, change configurations and then refresh the apps to see if they load faster than before. 

This practice is like baking a cake without measuring the necessary cups. 

Apart from this, some of the common challenges faced that make it necessary to optimize the performance are;

• Unnecessary use of server
• Slow page response
• Unnoticed app crashes
• Periods of app slow-down
• Not meeting the expected results

So, what’s a better approach?

Measure and take calculative steps- This is what is required!

Here are a few tips on how you can optimize the Angular performance;

Sure Shot Tips to Optimize Angular Performance in 2023

Lazy Load Modules

With the compilation of Angular application, webpack is used in the back-end to generate bundles that consume memory and reduce the speed of the application. 

To solve this issue, the lazy loading method is used, which splits the bundle into multiple modules and features and improves the application performance. 

Improvement in Change Detection

Change detection in Angular is a powerful mechanism that helps you to optimize performance metrics. But moving with constant practice isn’t getting you anywhere. 

Change detection allows you to update new entries and push updates. 

It reflects the component’s data changes and re-renders the app to reflect the changes. However, while talking about complex applications, change detection is a real challenge.

To manage the change detection, the three strategies that can be implemented are On-push, immutability, pipes instead of methods, and detach change detection. 

Web Workers for On-blocking User Interface

The process of data encryption and image resizing involves the main thread. While utilizing the main line, the user interface freezes. In such cases, users may find the application annoying. These processes are then shifted to a separate thread to avoid central thread involvement.

Some common types of use-cases for utilizing the web workers are;

• Complex calculation
• Content formatting in real-time
• Progressive web apps
• Extensive updates on the database
• Filtering of images

1. Limiting $watchers 

As you bind the data to your app, you create $watchers and $scopes. This is done by extending the app’s digest cycle, which causes lag. To reduce the digest cycle, you can reduce watchers’ usage, making the digestion processes smaller. 

2. Using $watchcollection replacing $watch

Use $watchcollection instead of $watch because the watch functions with two parameters and is faster than a watch with three parameters. 

// Use the relatively new watchCollection().

$scope.$watchCollection(

“collection”,

function( newValue, oldValue ) {

addLogItem( $scope.watchCollectionLog );

}

);

// Use the old watch() with default object equality,

// which defaults to using object REFERENCE checks.

$scope.$watch(

“collection”,

function( newValue, oldValue ) {

addLogItem( $scope.watchLog );

}

);

It seems like: $watch (‘value’, function (){}, true), whereas the third parameter, takes a longer time to execute and function. 

3. Disabling comments

Most angular apps have minimal features that do not require a separate directive for comments. Turning off the comments directives and CSS class can take off a significant load from the functions. 

4. Smaller DOM trees

DOM trees can slow down the performance of your app. So what’s the solution here? Keeping the structure small while ensuring great bundling in the program scripts. With such a practice, you can reduce the time taken by the app to load, hence increasing the overall app performance. 

5. Performance issues with Chrome Dev tools

To optimize the Angular performance, you must understand the app’s challenges. Without looking into the issues, you won’t be able to fix them the same. With the help of Chrome DevTools, such as Timeline and CPU profilers, you can check the bottlenecks in the performance of your apps. 

6. Don’t use ng-repeat repeatedly.

One of the significant causes of why your Angular application may be slowing down is due to the repeated use of ng-repeat repeatedly. Here, to increase the performance, you can implement its substitutes which are $interpolate. This is the provider that is used to render the global navigation. 

<bc-interpolate

  bc-string=”Item 0 matches ${0}, item 1 matches ${1}, etc…”

  bc-array=”[‘ZERO’, ‘ONE’]”

></bc-interpolate>

<!– Output:

  Item 0 matches ZERO, item 2 matches ONE, etc…

–>

7. Use the Protractor & other performance tools

With the usage of the Protractor, you would be able to improve the performance of your Angular app. Apart from this, you can also use tools such as NightwatchJS, WebDriverIO, etc. 

8. Unsubscribe from the observables

Turning a blind eye to the minor things in the application development can lead us to some significant setbacks in memory leaks. The main reason behind memory leaks is when our application fails to eliminate the resources that are not being used anymore. The observable has the subscribe method with a callback function to get the values emitted. 

9. Avoid computation in template files.

The template expressions are most commonly used in Angular. We often require a few calculations on the data we get from the back end. To achieve this, we deploy functions from the template, and the bound part runs on the change detection (CD) runs on the component. 

If the function takes a long time to wind up, it will result in a slow and laggy UI experience for the users. The template expressions must wind up quickly, and if highly computational, they should move to the significant components file and calculations beforehand. 

10. Using the trackBy option for Loop

It uses the *ngFor directive to loop the items and then displays them on the DOM. If not added with caution, it may damage the performance of the Angular app. 

Suppose we have the functionality of adding and removing the employees asynchronously. If you have a large object that contains the list of all the employees with names and email addresses, we need to go over the list and display the entire data on UI. With each addition and data removal, the detections run and create a new DOM for a new value while destroying the previous one. 

This significantly impacts the performance, as rendering the DOM is expensive. So, to handle this, the trackBy function is used, which keeps track of all the changes and updates only the required values. 

Closing Words

Not all the app optimization tricks and tips are worthy enough to be implemented in the Angular app to improve its performance. By looking at the app’s requirements, you must implement the recommendations that benefit your app and business. 

If you are convinced and are a suitable place that can help you enhance the performance of your angular app, you’re at the right place.

Connect with our team of experts and hire the best Angular developer today!