Generalized parsers for visual languages result to be more complex than the corresponding text parsers: their applications to ambiguous inputs with visual tokens scattered and/or connected on a 2d or 3d space are very difficult to trace without the support of proper visualization tools. In this work, we give a brief description of generalized parsers for visual structures and illustrate a tool for the visualization of its execution. To do this, we provide examples based on a Visual Generalized LR (VGLR) parser applied to flowcharts.