Traffic simulators are potent tools for vehicle modeling and analysis in urban areas. Effective management of the data generated is essential to ensure a continuous flow of vehicles and minimize congestion. Visualization of this data is crucial for a comprehensive and understandable analysis. However, there are few free tools available to generate compelling visualizations. To address this problem, we developed TrafficSim-Vis, a single-page application for visualizing traffic data from Multi-Agent Transportation Simulation (MATSim). TrafficSim-Vis was tested with vast public scenery traffic data from Santiago (Chile). As a result, TrafficSim-Vis offers an interactive and available interface that allows one to analyze, interact, and explore different aspects of the simulated data, obtaining relevant information about the traffic simulation. Code and demo video is available at https://github.com/ChrisALoor/TrafficSim-Vis.git .