Hardware Testing Tools

Every test on this site runs on top of the Web Gamepad API, the W3C interface that exposes connected gamepads to JavaScript. When you plug in a DualShock 4, DualSense, or Xbox controller, the browser reports a standardized layout: 17+ digital buttons, two analog sticks with normalized values from -1 to 1, and analog triggers mapped to button indexes 6 and 7 with pressure from 0 to 1. We poll this data roughly every animation frame (~16ms) so each press lights up the on-screen SVG within a single refresh.

The Gamepad API ships in Chrome 35+, Edge 79+, Firefox 29+, Safari 10.1+, and Opera 22+. USB wired connections are the most reliable for testing — Bluetooth works but can drop packets at low battery. For keyboards we use the standard KeyboardEvent.code and KeyboardEvent.key fields defined by the UI Events specification, so every key except a handful reserved by the OS (Fn, media keys on macOS) can be captured.

No part of this pipeline sends data to a server. There is no telemetry on which buttons you press and no account layer to log into. If you close the tab, everything is gone.

Analog stick drift is unintended input reported by a gamepad while the stick is physically at rest. It is almost always a hardware problem: the small potentiometers inside each stick module wear down after millions of rotations, dust collects around the gimbal, or the internal spring loses tension and stops returning the stick to center. The Gamepad API still reports movement even though your thumb is nowhere near the stick.

Our circularity error percentage quantifies a related problem: how far the stick's traced path deviates from a perfect circle when you rotate it at full deflection. A healthy stick produces a smooth curve that stays within a few percent of the ideal radius. A worn stick shows flat spots, spikes, or asymmetric pulls. In practice, we treat a circularity error above ~15% as a meaningful signal that a stick is on its way out — at that point calibration can compensate temporarily, but the long-term fix is replacing the stick module. The PS5 DualSense uses a more refined module design than the DualShock 4, and drift is less common, but adaptive-trigger assemblies add their own wear surfaces.