Creating and managing UI Documents (UXML)

The currently open and active UI Document (UXML) asset name is displayed in both the Hierarchy pane as a root tree item as well as in the Canvas header inside the Viewport. An asterisk * next to the name indicates unsaved changes.

UI Builder will always start, by default, with a blank unsaved UI Document (UXML). This will display as <unsaved file>*.uxml. You can start working within this UI Document (UXML) and then create it as an asset on disk later when you save for the first time.

You can open an existing UI Document (UXML) by either:

1. Using the File menu inside the UI Builder's Viewport pane toolbar and choosing Open...
2. Finding the document in the Project tab of the Library pane and either right-clicking and choosing Open in UI Builder or clicking the little box icon to the left of the tree view item.
3. Finding the document in the Unity Project Window and double-clicking on it. Note, if you already have the document open in the UI Builder and you double-click on it in the Unity Project Window, the UI Document (UXML) will open using your default text editor or IDE.

You can save any changes to the active UI Document (UXML) by using the File > Save menu in the UI Builder's Viewport pane toolbar. Ctrl/CMD + S might also work but the UI Builder window needs to be in focus. Note that the Unity project-wide Save will not save the active UI Document (UXML) open in the UI Builder.