| Feature | AngularJS (1.x) | Angular (2+) |
|---|---|---|
| Architecture | MVC (Model-View-Controller) | Component-based |
| Language | JavaScript | TypeScript |
| Performance | Slower due to two-way data binding and digest cycle | Faster with one-way data binding and improved change detection |
| Mobile Support | Not optimized for mobile | Mobile-first approach |
| Dependency Injection (DI) | Limited support | Powerful DI system |
| Data Binding | Two-way data binding (can cause performance issues) | One-way data binding (more efficient) |
| Directives | Built-in directives like ng-model, ng-repeat | Improved directives, custom elements, and enhanced structural directives like *ngFor, *ngIf |
| Routing | $routeProvider from ngRoute module | @angular/router with lazy loading and guards |
| Forms Handling | Template-driven with ng-model | Reactive Forms and Template-driven forms with better validation |
| State Management | Uses $scope and $rootScope | Uses RxJS and NgRx for reactive state management |
| Testing | Uses Jasmine & Karma for unit testing | Improved testing with Jasmine, Karma, and Protractor for E2E |
| Backward Compatibility | No backward compatibility with Angular 2+ | Supports AngularJS migration via ngUpgrade |
| SEO & Server-Side Rendering | Limited SEO capabilities | Supports server-side rendering (SSR) with Angular Universal |
| Modularity | Everything in one module | Uses feature modules (NgModule) for better organization |
| DOM Manipulation | Requires jQuery or $element | Uses a Virtual DOM-like mechanism for optimized rendering |
| Support & Future | No longer actively maintained | Actively developed with regular updates |
Which One Should You Use?
- Use Angular (2+) if you’re starting a new project for better performance, maintainability, and future updates.
- Use AngularJS only if maintaining a legacy project.