[Jetpack Compose Glimmer](https://developer.android.com/develop/xr/jetpack-xr-sdk/jetpack-compose-glimmer) is your UI toolkit for building rich, ambient
experiences for display AI glasses. As you develop your Jetpack Compose Glimmer
UI, use composable previews to visualize and iterate on your designs quickly and
efficiently. Composable previews give you a live, interactive rendering of your
Jetpack Compose Glimmer UI components directly within Android Studio. These
previews eliminate the need to continuously build and run your app on an
emulator or physical device for every small UI change, dramatically accelerating
your development cycle.  
[![](https://developer.android.com/static/images/picto-icons/plus.svg)
See also
If you are new to composable previews in Android development, see the general Compose documentation.
arrow_forward](https://developer.android.com/develop/ui/compose/tooling/previews)

## Preview Jetpack Compose Glimmer UI components

1. Open your XR project in the latest Canary build of Android Studio.
2. Verify that your composable function is annotated with the `@Preview` annotation.
3. In **Code** view, click the settings
   **Preview configuration picker** for the composable function.

4. From the **Device** drop-down menu, select **AI Glasses**.

   This adjusts the preview surface to match the unique resolution and aspect
   ratio of an AI glasses display.

   ![Select AI Glasses for the device in the composable function preview
   configuration.](https://developer.android.com/static/images/develop/xr/jetpack-xr-sdk/glimmer/preview-configuration.png)
5. Select either the **Design** or **Split** view to see the preview.

   ![The composable preview is shown in the Split view for a simulated AI
   Glasses
   device.](https://developer.android.com/static/images/develop/xr/jetpack-xr-sdk/glimmer/composable-preview.png)

## Adjust the preview environment

Glasses use an additive, transparent display. This characteristic means the
display can only add light; it can't create black. With an additive display,
black is not a color---it appears 100% transparent. The Compose preview provides
an approximation that helps you understand how the UI behaves in different
viewing conditions.

To simulate different viewing conditions, click the environment icon in the
preview pane toolbar. Try different background options (for example, Light,
Dark, or Busy) to check whether your text and components have adequate contrast
and visibility.