Angular 2 vs Angular 4 – Which One Fits Your Frontend Development Requirement?

24 / Aug / 2017 by Poulomi Nag 0 comments


The year 2015-2017 saw a host of new frameworks from the house of JavaScript. Though several of their offerings did fail to make a resounding impact, Angular and React survived the test of time to become the go to frameworks for successful Angular development. With several frameworks have made headway in the world of application development, Angular has found a special place as one of the best open-source JavaScript frameworks.

This article focusses on the basic comparison between Angular2 and Angular4 and whether or not it is good enough to make a switch. First, let us explore in detail the various features and highlights of Angular2 to be able to make a viable comparison with its successor.

Angular 2: The Highlights

The version two was primarily aimed at the development of mobile applications allowing developers to create a cross platform environment for their applications.The key highlight of Angular 2 was the elimination of various supplementary modules from Angular’s core which simplified the process thereby improving the performance. The supplementary modules have now found their way to Angular’s ever-growing library of modules where the users can effectively choose and select the components they want while leaving out the redundant components.

Angular 2 was specifically aimed at ES6 and “evergreen” modern browsers. The plus point of these browsers is that these automatically update to the most recent version. While developing for these browsers, Angular 2 provides various hacks and workarounds that allow developers greater freedom build their code. Angular 2 eliminates several hindrances that existed previously.  

Angular 2: Features and Performance

Angular 2 was developed on AtScript, which is a superset of ES6. Traceur compiler combined with ES6 was employed to process Angular that enables it to generate ES5 code. It utilizes TypeScript’s syntax to create runtime type assertions instead of compiling time tests.  However, it is not mandatory to use AtScript to compose Angular apps. You can alternatively use plain JavaScript or ES5 to attain effective results. Let us delve deeper into the various key features of Angular 2.

Renewed Dependency Injection (DI):

Dependency Injection was one of the key factors that set Angular apart from its primary competitors. Dependency Injection refers to a program design pattern where a specific program effectively gets hold of its dependencies instead of producing them. Dependency Injection is very helpful in cases of modular development and element isolation. Despite that this DI has faced several obstacles since the era of Angular 1.x. Angular 2 finally came with the answers to these problems along with some of the missing features like child injectors and lifetime/scope control.


One of the main advantages of Atscript is that it supplies useful tools that can help functionally link metadata. This eases out the process of building the object instances by supplying the essential material into the DI library. The information entered will check for the relevant metadata when a function is called, or a class instance is created. A developer can also easily override the parameter information by hitting the “Inject” annotation.

Child Injectors:

A child injector has the privileges such that it inherits all of the functionalities possessed by its parent injectors, but it also comes with a capacity to override them at the child level. This capability provided by Angular 2 gives the developer a free hand to call out and mechanically override several components under a variety of scopes as the situation would demand.

Instance Scope:

Instance scope controllers which come with the improved DI library have a definite edge when used with the child injectors. Child injectors combined with scope identifiers heightens the horizons of the instance scope controllers.  

Dynamic Loading:

This feature was introduced in Angular 2 for the first time and was not supported by its predecessors. Angular 2 boasts of its ability to allow programmers to add new controls or directives as and when needed without any scheduling needed.


Angular 2 supports an asynchronous procedure of template compilation. The module loader loads dependencies simply by referencing them at the part component as in essence, the code relies on the ES6 module.


Angular 2 effectively works with 3 primary directives mentioned as follows:

  • Component Directives: Component directives aim at making components reusable by capturing logic in HTML, CSS and JavaScript.
  • Decorator Directives: These directives can be employed to decorate various elements which may include hiding/showing of elements by using ng-hide/ng-show or by adding a tooltip.
  • Template Directives: Template directives can help turn HTMLs into reusable templates.  One can effectively use the directive writer to instantiate this template and its insertion into the DOM by using the likes of ng-repeat and ng-if.

Child Router:

The Child router converts every part of the program into a compact application by carrying out its supply by its own router. It allows the developer to summarize the entire feature collections of a program.

Screen Activator:

Angular 2 allowed the developers exercise a superior domination on the navigation life cycle by appointing a set of can* callbacks.

  • canActivate: This allows or prevents navigation to the new control.
  • activate:  This responds to successful navigation to the new control.
  • canDeactivate: This prevents or allows navigation away from the old controller.
  • deactivate: This responds to a successful navigation away from the old controller.


Angular 2 built all the logic using a pipeline architecture which made it exceedingly easy to add one’s actions into the pipeline or remove default ones. It’s asynchronous characteristic allowed developers to authenticate a user or load information for control by making server requests while it is still in the pipeline.


Angular 2.0’s logging service known as diary.js is a highly conductive aspect that helps to measure where you are investing maximum time in your program which in turn allows you to identify bottlenecks in your code.


Angular 2 has had $scope removed from it. This imminent demise of the controller ($scope) is orchestrated to put a renewed emphasis on components. A huge advantage in respect to transitioning to component based apps is that developers now can easily define their interfaces. Additionally, it allows for the HTML elements to have an easily mappable interface for events, attributes, and properties.  

Angular4: What’s New?

Even though Angular 2 was a significant upgrade from its predecessors, Angular 4 takes it forward with some new features and improved capabilities.

Let us examine one by one how Angular 4 has secured itself an edge over Angular 2 and how AngularJS development companies can leverage it.

Faster and Compact

Angular 4 applications are smaller as they consume less space and run quicker than its older versions. The team working behind Angular are continually making small improvements on a regular basis to iron out the inconsequential technical glitches that may exist.

Significant View Engine Improvement

Angular 4 series have come up with several changes which include several view engine tweaks to diminish the size of the generated code for various components by as much as 60 percent. This version update has claimed to reduce huge production bundles to mere kilobytes.

Revolutionary Animation Features

Angular 4.2 has introduced a whole new lease of animation features that facilitate multi-element and reusable animations for effective Angular development and also has a host of full-blown router-level animations. Angular 4 comes with its own set of animations extracted from the Angular core, which leaves your creation package free of the excess code in case you don’t use the animation attribute. This feature would also make it possible for the developers to find the docs easily and tap the auto-completion feature. By importing the Browser Animations Module out of @angular/platform-browser/animations, developers can now add animations to the main NgModule.

Enhanced *ngIf and *ngFor

One of the main features that Angular boasts of are an improved template binding syntax. The improvement of the *ngIf and *ngFor comes after significant criticism of for the lack of the “else” and “if-then-else” clause. Now, developers can employ an if/else design syntax, or introduce local variables like “if” to unroll an observable.

Angular Universal

“Server-side rendering for Angular apps” aka Angular is the name for the middleware that exists between node.js and Angular. This feature brings together the user experience and high-performance single page apps combined with the SEO readiness of static pages. Initially, a community driven project, Universal is now a vital part of the Angular team. Angular 4 make available a majority of codes prepared by the Universal team on its server which is a highly recommended repository by developers across the world.  

Compatibility with Typescript 2.1 and 2.2

Angular 4 has been upgraded to accommodate the more recent versions of Typescript. This TypeScript release compatibility allows better type checking and enhanced IDE features for Visual Studio Code. This improvement will help enhance the rate of ngc with superior type checking features during program execution.


Angular has come a long way since Angular 1.x to reach the version that prevails today. This evolution of Angular is expected to continue to bring in more revolutionary features to make the development team’s job easier.  Given that we are all competing in an experience economy, it is important to provide users with a smooth and consistent experience. Product engineering goes further than just delivering a functionality and includes the deliverability of a seamless experience. Even though Angular can be a little challenging to adapt to at first, but those who are familiar with the functioning of Angular 2, will find it simpler to adopt Angular 4.


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