What’s the difference between AngularJS, Angular2 and Angular4?

One question that often comes out is “What is the basic difference between AngularJS, Angular 2 and Angular 4 and how to jump from Angular 2 to Angular 4?”

Angular JS was introduced in 2010 as a JavaScript framework for building client side single page web applications. So it gained popularity and the Angular team at google started to add some more features to the core. But the framework was not designed with the needs of today’s applications in mind and moreover it was totally complex. So the Angular team decided to rewrite the entire framework using TYPESCRIPT and as a result Angular 2 was released in mid 2016. The new Angular framework is completely different from the previous version and we can think of it as a completely different framework compared to the earlier one.

The decision was frustrating to most of the developers since a lot of applications have been designed using AngularJS. I personally liked the direction that Angular developers took in rewriting the entire framework according to the needs of modern software development. It is lot cleaner and much easier to understand and to work with.

 After a few minor upgrades to Angular 2, something strange happened. It went out to Angular 2.3 and suddenly Angular 4 came out. Lot of developers including myself were confused so as to what happened to Angular 3.We thought we had missed something big here. 


But there were no major changes included from Angular 2 to Angular 4.Infact it wasn’t even a major upgrade. So let me explain what happened!

Angular consists of a few different libraries that are distributed as separate node packages via NPM (Node Package Manager).For example, we have the CORE library (@angular/core) that is used in every Angular application. We have the COMPILER library (@angular/compiler), HTTP library (@angular/http) which is used to make http requests and the ROUTER library (@angular/router) which is used to add navigation to our application and a few other libraries. All these libraries were versioned the same except the ROUTER library (which is 3.3.0). So inorder to align these versions and avoid confusion in the future, angular team has decided to go directly to Angular 4.Angular 4 is not a major upgrade to Angular 2 and we can think of it as Angular 2.4.

After all this confusion about the Angular versions, the team decided to drop the version suffix and simply call the framework “ANGULAR”. So now we have two kinds of Angular.
·       AngularJS (1.x)
·       Angular (2+)

So it is recommended to use the word “Angular” rather than “Angular 2” or “Angular 4”.We should use versions only when we talk about a specific release. For example, when we want to upgrade from Angular 4 to Angular 5.Then everybody knows what the scope of this upgrade is and what are the potential upgrade changes that can impact an application.
This is all about Angular Version History.

Thanks for reading!


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