Screen screen = Screen.getPrimary(); javafx.geometry.Rectangle2D bounds = screen.getVisualBounds(); primaryStage = stage; primaryStage.setX(bounds.getMinX()); primaryStage.setY(bounds.getMinY()); primaryStage.setWidth(bounds.getWidth()); primaryStage.setHeight(bounds.getHeight()); primaryStage.initStyle(StageStyle.UNDECORATED); primaryStage.show(); new Flow(IndexController.class).startInStage(primaryStage);