Earlier versions of AngularJS have undergone many amazing features thus causing you to make changes in your applications codes. First we need to focus on why you should migrate from AngularJS to Angular. Angular was released in 2012. If yod donot follow the rules for writing codes and you have many things on the screen then your application will become slow.

Angular is based on TypeScript. The template engine has many directives and AngularJS allows developers to specify custom directives. AngularJS has standard directives. Angular has a Model-View-Controller based architecture. Angular uses components and directives instead of controllers and scope. They control the applications view and page logic. Angular supports both web and mobile applications whereas Angular supports only web applications. AngularJs was meant for designers so the performance is limited. Angular provides high speed performance, developers can also use them. Angular supports hierarchical dependency injection. Angular has better structure which makes it easy to manage. 

Tools to migrate AngularJs to Angular

ngMigration assistant is a tool that can be operated using command prompt. It will give simple and clear guidance for how to migrate your application. It analyses your AngularJS app and gives you recommendations about how to approach your application. 

Here is an example of angularJS phone catalog app.

ngMigration assistant tool provides statistics about what it found in the application. Also provides you steps for migrating AngularJS app to Angular.

This is how it will look like.

Another way for migrating is use ngMigration Forum. It is a community where you can find information about migration paths, tools.