@# Portals The `Portal` component renders its children into a new "subtree" outside of the current component hierarchy. It is essential piece of [`Overlay`](#core/components/overlay), responsible for ensuring that the overlay contents cover the application below. In most cases you do not need to use a `Portal` directly; this documentation is provided simply for reference. @## JavaScript API The `Portal` component is available in the __@blueprintjs/core__ package. Make sure to review the [general usage docs for JS components](#blueprint.usage). The `Portal` component functions like a declarative `appendChild()`, or jQuery's `$.fn.appendTo()`. The children of a `Portal` component are appended to the `` element. `Portal` is used inside [`Overlay`](#core/components/overlay) to actually overlay the content on the application.

A note about responsive layouts

For a single-page app, if the `` is styled with `width: 100%` and `height: 100%`, a `Portal` may take up extra whitespace and cause the window to undesirably scroll. To fix this, instead apply `position: absolute` to the `` tag.

@interface IPortalProps @### React context `Portal` supports the following options on its [React context](https://facebook.github.io/react/docs/context.html). To use them, supply a child context to a subtree that contains the Portals you want to customize. @interface IPortalContext