What is lazy loading in Angular

Lazy loading in Angular is a technique used to load only the necessary pieces of functionality (such as modules or components) when they are required, rather than loading everything up front. This approach can significantly improve the initial loading time of an Angular application, especially for larger applications with many modules.

In Angular, lazy loading is typically implemented using the Angular Router. Here’s how it works:

1. Routing Configuration: Modules or components that should be lazy loaded are specified in the route configuration using the loadChildren property instead of component.

const routes: Routes = [

  { path: 'lazy', loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule) }

];

Here, loadChildren takes a function that uses dynamic import to load the module when the route is visited.

2. Separate Bundles: When the Angular CLI builds the application, it creates separate bundles (JavaScript files) for lazily loaded modules. These bundles are loaded asynchronously when the corresponding route is activated.

3. Benefits:

• Faster Initial Loading: Only essential code is loaded initially, reducing the initial payload size and speeding up the application startup.

• Improved Performance: Users only download the code they need as they navigate through the application, improving perceived performance.

• Better Code Organization: Modules can be logically separated and loaded on demand, making the application more maintainable.

4. Usage: Lazy loading is commonly used for feature modules, admin modules, or modules that are not required for the initial view of the application but might be accessed later.

Overall, lazy loading is a powerful optimization technique in Angular that helps in achieving faster load times and better user experience, especially for larger and more complex applications.