Name any top website from any niche, and you will find Angular behind the development–Google, YouTube, PayPal, iStock Photo, Upwork, and the list is a never-ending one.

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It won’t be an exaggeration to say that Angular remains one of the most sought-after frameworks among the numerous other JavaScript frameworks.

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The chart shows the usage of Angular over a period of time. The primary intent behind the development of Angular was to address numerous challenges associated with single-page apps. However, today, top companies in their industries are betting on it.

It clearly shows that the wave of Angular is not going to subside anytime soon, and more web and mobile apps are coming out of the framework. As a leading our focus is on improving the performance of your existing Angular apps. From the bag of our experience, we have prepared an Angular performance checklist that you can use for Angular development.

This guide will also talk about challenges and tips to optimize angular performance.

What are the common challenges faced by Angular developers?

App performance is an influential factor in determining the end user’s experience. Want to know how to find out if your app is performing well or not?

Here are some determiners:

  • A sharp reduction in the traffic of your app visits.
  • A decrease in the engagement rate.
  • An increase in the bounce rate.

Once you start noticing one or all of the above-mentioned determiners, it is time that you take your Angular app performance seriously. Now, instead of looking at how wrong things are going in the backend, it is crucial that you focus on why things are going wrong.

Let’s look at some of the common challenges that hinder the Angular app from performing at its truest potential. Our expert Angular developers have also found solutions to offset these challenges

Let’s look at some of the common challenges that hinder the Angular app from performing at its truest potential. Our expert Angular developers have also found solutions to offset these challenges.

Angular App Showing Frequent Slowdown:

Let’s understand the end user’s psychology. A modern individual lacks patience. In such a case, when an app slows down from working at its actual speed, it causes frustration. The user then decides to force stop the app or move to another similar app.

How to resolve periodic slowdown?

Our Angular developers of Peerbits say that you should use PWA or static cache content to optimize your hosting. If you still face the issue, you can directly hire Angular experts since you can’t afford to lose the traffic.

Angular app using server space unnecessarily:

Unnecessary server usage creates a direct threat to an app’s security. Numerous cyberattacks are due to the security loopholes in the server. As a result, the privacy of user’s is also compromised. In addition, it slows down the application’s functioning.

How to resolve unnecessary use of server?

You can get rid of the unnecessary change detection that leads to slow performance of your application. If the issue still persists, it is time to take it to experts or hire dedicated Angular programmers.

Angular app shows slow page response:

The user taps/clicks on a feature and waits for eternity–this is the case when your app has a slow page response. Typically, the attention span of a user is about 5 seconds. If your app doesn’t deliver what the user needs in this time bracket, you are trading your app user with a slow response.

How to resolve slow page response?

The best solution to tackle slow page response is to use OnPush at required places. This can help you optimize the performance of your Angular app. In case you are unable to do so, you can hire an experienced Angular team from Peerbits to help you tackle Angular performance issues.

Angular app crashes unexpectedly:

Let’s think of a scenario where your end user is using your app. It crashes out of nowhere, leaving behind the dilemma of–to use or not to use it–for the user. In such a case, instead of looking at the other best frontend framework, you should look for a solution within Angular.

How to resolve an app crash?

Numerous requests made to the server at the same time may lead to an unexpected app crash. You can slow HTTP response or leverage a good service aggregator such as GraphQL to prevent your app from such a sudden attack. If you do not know about any good service aggregator, you can seek consultation from an experienced Angular development company.

Angular app shows unexpected pop-up of errors:

Now unexpected errors may pop up due to a heavy load of data streams in your Angular app. This can be the result of the real-time data stream that you encourage to retain your end user’s attention to your app.

How to resolve an unexpected pop-up of errors?

When your app encounters such an issue, you can bring down the size of the bootstrap logic. This should resolve the issue. However, when you are unsure about it, you can hire Angular programmers to assist you.

Angular app not compatible with migrated technology:

When your app is not meeting the expectation of the migrated technology, it might not function in the desired manner. As a result, the end user’s experience might get affected.

How to resolve compatibility issues?

One of the best solutions that our Angular developers have found is, you can eliminate the redundant mathematical recomputations from your application. While doing so, ensure that you are not removing the useful ones. This does sound a bit tricky, and so, if you need technical guidance, you can hire dedicated Angular engineers for this task.

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What are some of the best tips to optimize angular performance?

We have witnessed numerous clients, who have the Angular vs React vs Vue dilemma, as soon as they start facing issues in their Angular application. However, we explain to them about the benefits of Angular and provide them with the best tips for optimizing mobile applications.

If you want to develop an Angular application, we have highly effective tips for you. For better understanding, we have segregated the tips to boost your Angular app performance into two categories.

Tips for angular runtime performance:

You can increase your Angular runtime performance by two methods–an organization of the app and functions and language that build your app. However, before attempting to improve your runtime performance, it is recommended that you compile and benchmark your web and mobile app using full optimization.

You can also use good performance analysis tools to determine the actual source of issues. Below are effective Angular performance optimization techniques to improve your runtime:

Ensure to do Ahead-of-Time (AoT) Compilation:

Ahead-of-time compilation (AOT compilation) is the practice of converting an Angular HTML as well as TypeScript code into more efficient code. This helps in turning the JavaScript code into a better performing application.

The chart represents how the ahead-of-time compilation happens:

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AOT compiler compiles your Angular web or mobile app as well as libraries at the build time. It extracts metadata to determine the modules that Angular needs to manage.

There are three phases of AOT compilation.

  • Phase I represents code analysis, wherein the TypeScript compiler, as well as AOT collector, generates a representation of the source. li>
  • Phase II is code generation, wherein the StaticReflector of the AOT compiler determines the metadata that was gathered in the previous phase.
  • Phase III is template type checking, wherein the Angular template compiler leverages the TypeScript compiler to confirm the binding expressions.

Change detection in your angular app:

Change detection is a strategy that default change detectors leverage to identify changes. When the change detection is set, it shows its effect during the next time when it is triggered.


    enum ChangeDetectionStrategy {
        OnPush: 0
        Default: 1
    }

The following code shows the right way to use the change detection strategy. In the code mentioned above, OnPush: 0 shows that the strategy has been invoked. It applies to all the child directives.

The Default: 1 represents that you can use the CheckAlways strategy, wherein change detection happens until it is deactivated deliberately.

Use onpush & immutability:

OnPush refers to the concept of detecting a value much faster when reference types are immutable objects. It ensures that the changes in component trees are skipped when triggering is not important. It selects a specific branch for undergoing change detection.

In a nutshell, OnPush helps in minimizing change detection. However, in some scenarios, optimization is required. Here, you can make use of immutable objects for the reduction in complexities. It helps in rendering the DOM. On the other hand, mutable objects don’t return a reference while values get changed. In addition, if you want some rendering to happen, you can use immutable.js.

Below is where you can find the difference between mutable & immutable objects:


    @Component({ 
        selector: 'person', 
        template: `{{person.name}} lives at {{address.street}}, {{address.city}}` 
    }) 
    class DisplayPerson {
        @Input() person: {name:string}; 
        @Input() address: {city:string, street:string}; 
    }

Immutable Object


    @Component({selector: 'typeahead', templateUrl: 'typeahead.html'}) 
    class Typeahead {
        @Input() options: string[];
        @Input() initOption: string;
        @Output() change = new EventEmitter();
        scrollingPosition: number; 
    }

Here, we are considering that reference types are mutable. Hence, we are simply working with mutable objects but making it look as if we are working for immutable objects.

If you are wondering how to execute the OnPush strategy, below is the example:


    @Component({
        selector: 'home',
        template: `
        <newsletter [user]="user" (subscribe)="subscribe($event)">newsletter>
        <button (click)="changeUserName()">Change User Namebutton>
    `})
    export class HomeComponent {
        user: User = {
            firstName: 'Alice',
            lastName: 'Smith'
        };
        constructor(private newsletterService: NewsletterService) {
        }
        subscribe(email:string) {
            this.newsletterService.subscribe(email);
        }
        changeUserName() {
            this.user.firstName = 'Bob';
        }
    }

Here, you need to be careful about the complexity that comes with the use of its API is that immutable.js does not support interfaces. However, it is still an easy way to make a switch.

Detach change detection for your angular app:

When you have a heavy computation, it is a good idea to avoid change detection as it raises the application load with the use of numerous components. In case there are numerous events to manage, it turns out to be a cost-intensive approach.

When you apply OnPush, rendering child elements can be difficult in some applications. Here, you can reduce the change detection by detaching it at the time when data is required to improve the runtime for performing actions. Below you will find an example for detaching change detection in Angular:


    abstract class ChangeDetectorRef {
        abstract markForCheck(): void
        abstract detach(): void
        abstract detectChanges(): void
        abstract checkNoChanges(): void
        abstract reattach(): void
    }    

Decrease recalculation of values using pure pipes for angular apps:

Pure pipes are known for reducing the recalculation of values, a distillation of outcomes, and complication numbers. It returns value only when the input is different from the previous one. You can easily reduce the use of methods by simply changing it with pipes. A pipe can be called when you change input values during every change detection.


    import { Pipe, PipeTransform } from '@angular/core';
    @Pipe({
        name: 'applyPure',
        pure: true // immutable (value) inputs & pure fn (function)
    })
    export class ApplyPurePipe implements PipeTransform {
        transform(value: any, fn: Function): any {
        return fn(value);
        }
    }
    @Pipe({
        name: 'apply',
        pure: false // any (value) inputs & any fn (function)
    })
    export class ApplyPipe implements PipeTransform {
        transform(value: any, fn: Function): any {
        return fn(value);
        }
    }  

You can use pipes to change dates, currency amounts, strings, and similar data. These are single functions that take an input value and send output in the form of a transformed value.

Web workers for non-blocking user interface:

Some of the processes, such as encryption of data as well as resizing of graphics, include the main thread. However, it freezes the user interface. As a result, the user gets annoyed with the Angular app.


    if (typeof Worker !== 'undefined') {
        // Create a new
        const worker = new Worker('./app.worker', { type: 'module' });
        worker.onmessage = ({ data }) => {
            console.log(`page got message: ${data}`);
        };
        worker.postMessage('hello');
    } else {
        // Web workers are not supported in this environment.
        // You should add a fallback so that your program still executes correctly.
    } 

Web workers use these complex processes to eliminate the inclusion of main thread in the background processes while maintaining an effortless operation of UI. There are numerous types of use cases for web workers, which include image filtering, data update on a database, complex calculations, real-time content formatting, and progressive web app.

Optimize events for faster doms:

It is a common fact that optimization of events is necessary to eliminate unnecessary loading as well as service requests. When you want faster working DOMs, you need to make the business logic compact. Slow DOM leads to delay in click events and delivers a bad user experience.


    @Component({
        selector: 'sample',
        template: `
            <span>I am first span</span>
            <ng-container [ngTemplateOutlet]="tpl"></ng-container>
            <span>I am last span</span>
            <ng-template #tpl>
                <span>I am span in template</span>
            </ng-template>
        `
    })
    export class SampleComponent {}

When the optimization is not required, components of the Angular app can take more time to click events. You can optimize such events by simply modifying the business logic, which needs the shortest possible way.

Optimize dom manipulation for better performance:

DOM manipulation is necessary for the performance and speed of an application. The DOM manipulation leverages ngFor directive for the management of an array of iterable objects.

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You can leverage the best practice layout tips. In addition, you can minimize the number of CSS rules to optimize the performance of your Angular app. When you use it properly, you can effectively handle iterable objects, thereby boosting the performance and speed of an application.

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What are some of the best tips for optimizing load-time performance?

There are numerous ways wherein you can optimize the load-time performance of your Angular applications. You can check for three aspects while performance-tuning of Angular apps–Investigate the error, fix the error, and measure the outcome. If the issue still persists, again go back to the source of the problem and follow the subsequent steps.

If you are unable to do so, it is recommended that you hire an Angular expert to handle the issue for you. In other cases, when can directly access the tips:

Lazy loading for better efficiency of program’s operation:

By using lazy loading, you can easily boost the productivity of your module. Lazy load in an Angular application is a default feature that helps experts with loading as required. Also, by utilizing the lazy loading feature module, you can prevent other redundant files from getting loaded.

Example of Lazy loading:


    import { NgModule } from '@angular/core';
    import { Routes, RouterModule } from '@angular/router';
    import { CustomersComponent } from './customers.component';
    const routes: Routes = [
        {
            path: '',
            component: CustomersComponent
        }
    ];
    @NgModule({
        imports: [RouterModule.forChild(routes)],
        exports: [RouterModule]
    })
    export class CustomersRoutingModule { }

You can use lazy loading to load only the modules that are required to reduce the initial load time. Here, you don’t need to load the entire app. As a result, the load time taken for the overall app decreases.

Save your build from memory leak:

A memory leak is a critical issue to detect. It is extremely difficult to identify, tough to debug, and often tough to solve. However, the problem is not particular to only Angular. Memory leaks can be determined as the type of memory that’s not required but not released.


    export class ChildMemoryLeakedComponent implements OnInit, OnDestroy {
        componentId: number;
        public counter: number;
        public counterSubscription: Subscription;
        ngOnInit() {
        this.componentId = new Date().getTime();
        this.counterSubscription = timer(0, 1000)
          .pipe(tap(counter =>{
            console.log(`Counter ${this.componentId} ${counter}`);
          }))
          .subscribe(counter => {
            this.counter = counter;
          });
        }
        ngOnDestroy() {
        console.log(`Counter ${this.componentId} stopped at ${this.counter}`);
        }
    }

Memory leaks happen when some of the components are rerendered numerous times. Besides this, when the memory consumption spikes up over time, memory leaks can be created.

Remove unused code using tree-shaking:

Angular 2 brought in the tree-shaking feature. Tree-shaking is the feature that helps in removing any type of code that is not actually used in the application from the final bundle. It can be said that Tree Shaking is one of the effective techniques to decrease the time taken for building an application.

Example of tree shaking:


    export function drive(props) {
        return props.gas
    }
    export function fly(props) {
        return props.miles
    }

Then we have the following index.js file:


    import { drive } from modules;
    eventHandler = (event) => {
        event.preventDefault()
        drive({ gas: event.target.value })
    }

In simpler words, you can say that tree-shaking is used for getting rid of the unused code from the code base. The codes that are to be removed are dead code. Hence, once these types of codes with no use at all in the application are used, the time taken for rendering the app decreases significantly.

Preload & prefetch for instant engagement:

Preload and Prefetch are the two crucial attributes in a code that helps load the static types of resources quickly. If you want to understand the difference between preload and Prefetch, it is that preload has greater priorities than it holds.

Example of the attributes:


    abstract class PreloadingStrategy {
        abstract preload(route: Route, fn: () => Observable<any>): Observable<any>
    }

As a result, you can leverage Preload for the modules and functions that you think are essential for initial rendering. In addition, you can use Prefetch for the type of resources that are necessary after the site load.

Removal of third-party packages for smaller build:

When you wish to cut down on adding more size to your app built, it is crucial to leverage native JavaScript. The third-party APIs are usually used for increasing the size of the applications to make it more feature-rich.

However, in order to add numerous functionalities, the space of the app increases. This can lead to poor load time performance of your Angular application. When you have a smaller build, it means that the functionality of the app is very specific. In such a case, it is not a wise idea to add forced features into your application.

Server-side rendering through angular universal:

Server-side rendering is crucial for boosting the load-time of an Angular app. It is a process of rendering a server despite rendering of a browser. This is the case of typical Angular applications.

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The server-side rendering ranks most of the search engine results. We leverage server-side rendering for the top two reasons–for offering performance benefits for customers and search engine optimization.

Cache static content for lightweight user experience:

Are you wondering what caching static content is? These are progressive web apps with lesser load-time for Angular. Such types of web apps are a huge hit as the static caching of assets, JavaScript files, and CSS files happen.

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For numerous types of eCommerce applications, end users may not be able to install different types of apps. In such a situation, the possibility is to have a shortcut on the home screen, while having a similar experience like a native.

Important tips to improve the performance of your existing angular apps

Numerous developers, who lack experience in resolving issues popping up in the Angular app, take the React vs Angular route. This means that they don’t go in-depth with Angular; they simply switch it to the other JavaScript frameworks.

However, it is crucial that you stick to Angular, as it offers numerous benefits. If you think that the Angular performance issues that your application has cannot be tackled using the tips mentioned above, here are some of the additional tips for you:

  • You can leverage Uglify to reduce the code size through numerous code transformations such as elimination of white spaces, mangling, deletion of comments, and so on to boost the load-time performance of Angular app.
  • Though Google closure compiler is not supported by the Angular team, you can use this compiler to produce results that are smaller in bundle size when compared to Webpack.
  • When you are using Angular-cli, ensure that you mention the ‘build-optimizer’ flag for a production build. This will result in relatively smaller code.
  • If you have a larger app size, you can use RxJS 6 that turns the whole library tree-shakable, and, in turn, decreases the final size of your build.
  • You should unsubscribe observables for the creation of memory leak issues. Here, you do not need to unsubscribe all observables used within the Angular app. You should unsubscribe only when a subscription is created in a component.

What next?

Developing an Angular app is an easy task. The tough task is to optimize its performance for improving the experience of end users. You can use these tips for optimizing and fine-tuning your Angular app.

We have dedicated Angular developers, who keep on researching and exploring ways to boost the web and mobile app performance. So, when you feel under confident about web app development, you can always reach out to us to hire an experienced Angular team.

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