Play without blunders. See the board. Spot the threats. Plan attacks. Love chess but hate missing the obvious? Put visual intuition to work alongside analysis. Chess Visualizer is an educational tool that reveals the structure of a position at a glance: critical, weak, and contested squares—and how pieces attack, support, and constrain one another. Key features: - Attack rays and a heatmap. - Fully customizable visualization - colors and geometry. - Play online with a friend. Open source / MIT.