# Overlay (/docs/destinations/overlay)



<img alt="Overlay Destination" src="__img0" />

The Overlay is a floating, borderless window with customizable colors and styling, designed to display captions on screen on top of other content or applications.

This feature is part of the [Line 21 App](/docs/line-21-app), which you can install on your computer to manage your captions and other settings.

Explore the [Overlay documentation](/docs/line-21-app/overlay) for more details.

## Supported languages [#supported-languages]

The overlay can display [all languages supported by Line 21 as a source](/docs/languages/supported-languages).