Configure JavaFX Scene Builder
IntelliJ IDEA allows you to open .fxml files in JavaFX Scene Builder right from the IDE after you specify the path to the Scene Builder application in the settings.
Configure Scene Builder in settings
Download and install the latest version of Scene Builder.
In the Settings dialog (Ctrl+Alt+S) , select .
Click in the Path to SceneBuilder field.
In the dialog that opens, select the Scene Builder application (executable file) on your computer and click OK.
Apply the changes and close the dialog.
Download Scene Builder from the IDE
If your project doesn't have JavaFX Scene Builder, you will see a notification on the Scene Builder tab for .fxml files.
Click Download Scene Builder Kit in the notification to download and install the tool.
After that you can open .fxml files in Scene Builder right in the editor.
Open files in Scene Builder
When you open an .fxml file in the editor, there are two tabs underneath the editing area: the Text tab is for developing the markup, and the Scene Builder tab is for editing the file in Scene Builder.
Scene Builder 2.x. and later.
If you are using Scene Builder of the version 2.x. and later, the files will be opened in Scene Builder on the Scene Builder tab by default.
Scene Builder 1.x
If you are using Scene Builder of the version 1.x, the Scene Builder tab is empty. In this case, right-click the necessary .fxml file in the Project tool window and select Open In SceneBuilder from the context menu.