9 Ways to Improve AngularJS Performance

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9 Ways to Improve AngularJS Performance

To get maximum benefits from new and updated JavaScript frameworks, you must keep optimizing performance on regular basis.

· Performance Zone ·
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AngularJS is the most widely used web app framework nowadays, and its popularity graph is constantly rising after the arrival of its much-awaited version AngularJS 4.0. But we can see that almost every Angular expert still struggles with various issues that directly correlate to AngularJS performance, even though it has a lot of its own optimizations.

Today, online businesses are greatly affected by the performance of web technologies that they use for their respective projects. Hence, it becomes necessary to dig into all of the factors that are hurting their business growth.

But there might be cases in which the incorrect use of AngularJS methods restricts your application's stance in the market, so AngularJS performance optimization becomes an important need of every AngularJS development expert. That’s why we're listing nine ways to improve AngularJS performance in this blog.

Related Reading: Top 10 Advantages of Using AngularJS

Recently, a survey was conducted by Brazilian computer scientists who found interesting facts about what causes performance problems for AngularJS programmers. There is not much information about how AngularJS performs in the real world. But research based on surveys provide some pieces of evidence for it.

The survey came up with the following results:


  • 45% voted that the source code problem that affects performance.

  • Only 8% admitted to actually making changes.

  • Some respondents blamed the architecture of AngularJS.

  • Some of them blamed unnecessary two-way binding.

After so much discussion on AngularJS performance, now it’s time to see the nine ways through which you can improve AngularJS performance.

AngularJS performance can be easily measured by its digest cycle. The digest cycle can be taken as a loop. During this cycle, Angular checks if there is any change to all the variables watched by all $scopes. If $scope.myVar is defined in a controller and marked for watching, then Angular will monitor the changes on myVar in each loop iteration.

1. Batarang Tool to Benchmark Watchers

Batarang is a great dev tool from the Angular team that lowers your debugging efforts. Although it has many new features, some of them help you profile and track the performance of your AngularJS performance. Moreover, the watch tree determines which scopes are not destroyed as it seems to be if there is any increase in the memory.

2. Use of Native JavaScript or Lodash

Lodash boosts your application performance by simply rewriting some of the basic logic instead of relying on inbuilt AngularJS methods. If Lodash is not included in your application, then you would probably need to re-write everything in native JavaScript.

3. Chrome Dev Tool Profiler to Identify Performance Bottlenecks

This one is a handy tool that gives you the option to select which profile type you want to create. Record Allocation Timeline, Take Heap Snapshot, and Record Allocation Profile are used for memory profiling. After this performance optimization, your app will fully render in less than two seconds and users can freely interact with it then.

4. Minimize Watchers

AngularJS completely revolves around its digest cycle. Whenever a digest cycle is triggered, it loops over every binding to detect model changes. The amount of time taken in each digest cycle can be reduced by reducing the number of watchers. It also reduces application memory footprints.

5. ng-if Is Better Than ng-show

The ng-show directive toggles the CSS display property on a particular element, while the ng-if directive actually removes the element from DOM and re-creates it if needed. Further, the ng-switch directive is an alternative to the ng-if with the same performance benefits.

6. Don't Use ng-repeat

This is the biggest win for any app if it is not using the ng-repeat directive, so it is advisable to avoid ng-repeat and build the HTML using JavaScript. For vocalizing applications, the use of ng-if results in the addition of unnecessary watchers. The use of the ng-bind-html directive is a better solution to get rid of this problem.

7. Use $watchCollection (Includes Third Parameter)

Using $watch with two parameters is good — but using $watch with three parameters, i.e. $watch(‘value’,function(){},true), makes Angular perform deep checking (to check every property of the object). But this could be expensive. Hence, to resolve such a performance issue, Angular provides $watchCollection(‘value’, function(){}) which acts almost alike $watch with 3rd parameter except it only checks first layer of object’s properties at low cost.

8. Use console.time for Debugging Issues

If your application is struggling with debugging issues and effecting Angular performance, then use console.time, which is a great API.

9. Debounce ng-model

You can debounce the input with ng-model. For example, to de-bounce the search input like GOOGLE, you have to use ng-model-options=”{debounce:250}”. This makes the digest cycle get triggered no more than once per 250ms due to the changes in this input model.

Development time is at a premium nowadays, so you need a comprehensive framework such as AngularJS to run your business quickly out of the box.

After researching a lot, we have collected some other important tools to enhance AngularJS performance.

Check out the following list of four AngularJS performance enhancing tools.

1. Protractor

Protractor is the most powerful automated end-to-end Angular testing tool, which was developed by the Angular team. Protractor is built by combining some great technologies like NodeJS, Selenium, webDriver, Mocha, Cucumber, and Jasmine.


2. GulpJS

GulpJS is used for automating repetitive tasks, the streaming build system, and linting JavaScript using JSHint or ESLint.


3. TestingWhiz

TestingWhiz is one of the most user-friendly test automation tools because of its codeless scripting feature. TestingWhiz offers an end-to-end testing solution to test AngularJS applications. It has a variety of test commands to easily create tests related to AngularJS. With a more dynamic wait command, TestingWhiz synchronizes with the varying server wait times for AngularJS components.



WebdriverIO lets you control a browser or a mobile application with just a few lines of code. Your test code will look simple, concise, and easy to read. The integrated test runner lets you write asynchronous commands in a synchronous way so that you don’t need to care about how to handle a promise to avoid racing conditions. Additionally, it takes away all the cumbersome setup work and manages the Selenium session for you.



As we have seen, web development is changing rapidly due to the introduction of many new and updated JavaScript frameworks. To get maximum benefits from these frameworks, you must keep optimizing performance on regular basis.

AngularJS is a powerful framework to build web applications like no other. By improving AngularJS performance, developers become able to do more with less coding. Even the risk of producing “spaghetti code” is greatly reduced.

angularjs, javascript, optimization, performance

Published at DZone with permission of Samaira Sandberg . See the original article here.

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