Gamepad Tester: Test Your Controller Online

How to test a controller

1. Connect the controller with a USB cable or pair it over Bluetooth.
2. Press any button on it. Browsers hide controllers from web pages until you press a button (some also accept a large stick movement) while the page is open, so nothing appears before that.
3. Press every button and move both sticks and triggers. Each input lights up on the drawing and in the button list, and a tick marks every button that has worked at least once.
4. Use Measure drift, Vibration and Measure update rate below.

With several controllers connected, press a button on the one you want to see or pick it from the list.

Button numbers and the standard mapping

When the browser recognises a controller it reports the mapping standard and arranges the inputs in the W3C Gamepad API’s standard layout, so button 0 is always the bottom face button, whatever is printed on it:

Axes 0 and 1 are the left stick and 2 and 3 the right stick, each from −1 to 1 with up as −1. Triggers are analog buttons from 0 to 1. A controller without a standard mapping is shown by raw button and axis numbers, which can differ between browsers and operating systems.

Stick drift, deadzones and circularity

Let go of both sticks and press Measure drift, which averages two seconds of readings. A resting stick rarely reads exactly 0, and games ignore small offsets with a deadzone. For scale, Microsoft’s XInput documentation suggests default deadzones of 7849 and 8689 out of 32767, about 0.24 and 0.27, for the left and right sticks. A resting offset that approaches those values, or grows over weeks, is drift. It usually comes from worn sensors or dirt inside the stick.

The shaded circle on each stick shows the deadzone set with the slider. To test circularity, rotate a stick slowly around its outer edge a few times. The page records the furthest point reached in each 5° direction and reports the average gap to a perfect circle. A few percent is typical. Bulges at the diagonals mean the controller reports a square range, and a flat or dented side means the stick cannot reach its edge in that direction.

Vibration and update rate

Vibration uses the Gamepad API’s vibrationActuator. The strong motor is the low-frequency one in the left grip, the weak motor the high-frequency one on the right. Rumble works with many Xbox and PlayStation controllers in Chrome and Edge; support in other browsers and with other controllers varies. The Trigger rumble button appears only when the browser reports trigger motors, such as on an Xbox One or Series controller, and uses the strong motor’s strength for both triggers.

Measure update rate counts how often new data from the controller reaches the page while you move a stick. Browsers poll controllers at a rate of their own, so the result is the lower of the controller’s rate and the browser’s, not necessarily the USB polling rate of the controller.

If the controller does not appear

• Press a face button, not only a stick or trigger, while this tab is in front.
• Try another cable; some USB cables only charge and carry no data.
• Close game launchers and remapping tools that may take over the controller.
• On Windows, Chrome names every XInput controller “Xbox 360 Controller (XInput STANDARD GAMEPAD)”, whatever its brand.