Gamepad Tester

Buttons, axes and mapping

Buttons light up when pressed; analog triggers (LT/RT) show a value between 0 and 1 depending on pressure. Each axis is a stick along one direction: an analog stick produces two axes (horizontal and vertical) that range from −1 to +1, with 0 at center. The timestamp is the time stamp of the last frame the API read, it changes constantly while the controller sends signals, confirming the read is live.

A "standard" mapping means the browser recognized the common layout (same positions for A/B/X/Y, triggers and sticks as a typical controller), which lets most web games work without remapping. An empty mapping means the controller is exotic or uses a proprietary driver, the signals still appear, but at indices the game may need to reconfigure.

• Buttons: lit = pressed; triggers show 0 to 1.
• Axes: −1 to +1, with 0 at each stick's center.
• Standard mapping: common layout recognized.
• Timestamp: changes each read, confirms a live signal.

Testing for drift and a suspect button

Example 1, hunting stick drift: fully release both sticks and watch the axes. On a healthy controller, each axis sits very close to 0 (say, 0.00 to 0.03). If one axis stubbornly reads around 0.20 on its own, the character "walks" untouched, the classic drift symptom, caused by wear in the stick's potentiometer.

Example 2, a button that fails in-game: press the suspect button repeatedly and check whether it lights up consistently here. If it always lights here but fails in the game, the problem is the game's mapping/configuration; if it also fails here, the button or controller itself is faulty.

When to use it and what the symptoms mean

Use it when buying a used controller, after cleaning or replacing a stick, when setting up a new controller on a PC, or when you want to prove that the "lag" or dropout is hardware and not the game. It also confirms whether a Bluetooth adapter really delivers every button.

If the controller does not appear, many browsers only expose it after a physical interaction (press a button), a privacy protection against fingerprinting. Constant drift points to a worn stick; an axis that never reaches its extreme may signal a high dead zone or wear; buttons that never light here indicate a real physical fault.

• Controller not showing: press a button to "wake" the API.
• Axis off 0 at rest: stick drift.
• Axis that never reaches ±1: dead zone or wear.
• Button that never lights: physical button fault.