# Default

> The initial configuration on UI Toolkit start up. This is equal to UIToolkitInputBackendOption.InputSystemCompatibleBackend. This option will use the Input System package is available, and the old Input Manager if not.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine.UIElements](/engine/6000.5/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

> **Warning:**
>
> **Deprecated.** This enum only has one supported value. The Default backend should always be used, as it is more stable and covers all use cases.

```csharp
Default = 0
```