Gamepad Tester

This tester reads directly from the browser's Gamepad API, which exposes every connected controller as a live snapshot of button and axis values rather than a stream of press-and-release events. Roughly sixty times a second the page asks the browser for the current state of every connected pad and redraws the on-screen buttons and stick positions to match, so what you see is effectively real time.

Browsers only add a controller to that list once it has sent at least one input, a deliberate privacy limit that stops a page from silently detecting what hardware you have plugged in before you interact with it. That is why nothing appears until you press a button, and it is normal, not a fault with the tester or the controller.

Buttons report both a pressed state and an analog value between 0 and 1, which matters for triggers: a shoulder button is usually a hard on-or-off, but a trigger you can squeeze partway will show a value that rises smoothly as you pull it rather than snapping straight to 1. Sticks report as pairs of axis values from -1 to 1, one for each direction, plotted here as a dot inside a box so a full circular sweep should trace a full circle, not an oval cut short in one direction.

Most controllers report through the "standard" Gamepad mapping, a common layout the API defines so pages do not need per-controller code, and this is what the button labels assume. A controller without that mapping still sends everything, just potentially in a different order, which is why position and live response matter more than trusting a label outright when something looks off. Vibration, where supported, is requested through a separate haptics API and depends on both the browser and the specific controller implementing it.