A free web-based tool to diagnose gaming controllers without installing software. It provides instant visual feedback for joystick performance, including: Stick Drift Testing: Measure drift magnitude to see if your sticks move on their own. Circularity Check: Calculate the average circularity error to test precision. Input Visualization: View real-time X/Y coordinates and button presses. Works with all major gamepads, including ALPS, Hall Effect, and TMR sensors.