Angular Guards

Angular Route Guards

Version: Angular 21 (2025) Tags: Guards, Routing, Auth, CanActivate

References: Guards Guide • CanActivate

API Changes

This section documents recent version-specific API changes.

• NEW: Functional guards — Use CanActivateFn instead of class-based

• NEW: CanMatch guard — Prevent lazy loading of unauthorized code

• NEW: provideRouter with guards — Modern guard registration

• DEPRECATED: Class-based guards — Migrate to functional

Best Practices

• Create functional guard

export const authGuard: CanActivateFn = () => {
  const authService = inject(AuthService);
  const router = inject(Router);
  
  if (authService.isAuthenticated()) {
    return true;
  }
  return router.createUrlTree(['/login']);
};

• Use CanActivate for route protection

const routes: Routes = [
  {
    path: 'dashboard',
    canActivate: [authGuard],
    component: DashboardComponent
  }
];

• Use CanActivateChild for child routes

export const adminGuard: CanActivateChildFn = () => {
  const auth = inject(AuthService);
  return auth.isAdmin() || inject(Router).createUrlTree(['/unauthorized']);
};

const routes: Routes = [
  {
    path: 'admin',
    canActivateChild: [adminGuard],
    children: [...]
  }
];

• Use CanMatch for lazy loading

const routes: Routes = [
  {
    path: 'admin',
    canMatch: [authGuard],
    loadComponent: () => import('./admin/admin.component')
  }
];

• Use CanDeactivate for unsaved changes

export const canDeactivateGuard: CanDeactivateFn<CanComponentDeactivate> = (component) => {
  if (component.hasUnsavedChanges?.()) {
    return confirm('You have unsaved changes. Are you sure?');
  }
  return true;
};

• Use withComponentInputBinding

export const appConfig: ApplicationConfig = {
  providers: [
    provideRouter(routes, withComponentInputBinding())
  ]
};

• Use multiple guards

const routes: Routes = [
  {
    path: 'admin',
    canActivate: [authGuard, adminGuard],
    loadComponent: () => import('./admin/admin.component')
  }
];

• Pass data to guards

const routes: Routes = [
  {
    path: 'user/:id',
    canActivate: [userGuard],
    data: { requiredRole: 'admin' }
  }
];

export const userGuard: CanActivateFn = (route, state) => {
  const requiredRole = route.data['requiredRole'];
  // Check role
};