Angular2 router keep query string

I don't think there is a way to define that in the routes configuration.

Currently it is supported for routerLinks and imperative navigation to enable

• preserveQueryParams and
• preserveFragment

You can add a guard to the empty path route, where in the guard navigation to the /comp1 route is done.

router.navigate(['/comp1'], { preserveQueryParams: true }); //deprecated. see update note

router.navigate(['/comp1'], { queryParamsHandling: "merge" });

There is a PR to allow to configure preserveQueryParams globally.

Update note: from https://angular.io/api/router/NavigationExtras, preserveQueryParams is deprecated, use queryParamsHandling instead

Günter Zöchbauer's answer should work properly but, for some reason, it is not working for me at all. What did end up working was passing the queryParams directly instead of 'preserving' them.

This is what my guard looks like:

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
    (...)
    this.router.navigate(['login'], { queryParams: route.queryParams });
}

If you are navigating using HTML template then you can use

<a [routerLink]="['/page-2']" [routerLinkActive]="['is-active']" queryParamsHandling="merge">

Something to watch out for is that queryParamsHandling param is without the square brackets.

It turns out the undocumented way to do this without other hacks is to simply remove the leading slash in the "redirectTo" field. Since you are matching the full path you can have the certainty that it'll do what you want (i.e. no surprise url segments) and since it's no longer an absolute target, Angular will preserve the current query parameters.

So in this case

{
  path: '',
  redirectTo: '/comp1',
  pathMatch: 'full'
}

becomes:

{
  path: '',
  redirectTo: 'comp1',
  pathMatch: 'full'
}

Source: https://github.com/angular/angular/issues/13315