Abstract
This paper presents a visualization tool that works as a debugger to learn the minimal spanning tree. The tool allows the user to enter the graph as a matrix and then enable the user to visualize the execution of the algorithm step by step. During the visualization, the tool can handle and debug the errors that occurred by the user. Also, the tool gives the user feedback from the execution of the algorithm by storing the errors that occurred by the user. The teacher and students can use the tool inside and outside the class. The tool was evaluated by the students, and the results show that the tool enhances the understanding of algorithms.