Lazy loading in Angular refers to a technique where modules or components are loaded asynchronously only when needed, rather than loading the entire application at once. This helps improve initial loading times and reduces the overall bundle size, especially in larger Angular applications.
Here's how lazy loading works in Angular:
- Module Splitting: Angular applications are typically organized into modules. With lazy loading, you can split these modules into separate bundles.
- Dynamic Loading: When a user navigates to a certain route that requires a module or component that hasn't been loaded yet, Angular dynamically fetches that particular module's bundle from the server.
-
RouterModule & loadChildren: In Angular, lazy loading is often implemented using the
RouterModule
and itsloadChildren
property within the route configuration. Instead of using thecomponent
property, you specify aloadChildren
property with the path to the module to be loaded lazily.
For example:
const routes: Routes = [
{
path: 'lazy',
loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule)
}
];
Separate Bundles: When using lazy loading, Angular creates separate bundles for different modules. These bundles are fetched by the browser only when necessary, reducing the initial payload size.
Benefits of lazy loading in Angular:
- Faster Initial Load: Only essential modules/components are loaded initially, reducing the initial load time of the application.
- Improved Performance: Smaller initial bundles lead to faster rendering and improved performance, especially on slower network connections.
- Better User Experience: Users experience faster page loads and can start interacting with the application sooner.
It's important to strategically use lazy loading in larger Angular applications, especially when dealing with multiple modules and complex routing structures, to optimize performance and provide a smoother user experience.