Duplicate "id" attribute in Angular 2 component

You can pass id as expression:

<my-checkbox [id]="'hello'">Check me</my-checkbox>

In this case component tag does not contain id attribute in DOM, it contains only attribute ng-reflect-id, which does not affect default behavior for label.

I would simply rename the checkbox's id (and hence the label's for attribute) so that it doesn't clash with the component's id, like so:

<input id="{{ id }}-checkbox" …>
<label for="{{ id }}-checkbox">…</label>