Gamepad Tester

Analog stick drift is the most common controller failure, and it is the reason most people come to a gamepad tester in the first place. A worn or dirty stick sensor stops reporting a clean zero when you let go, so the controller tells the game the stick is being pushed even though your thumb is off it. In play that shows up as a character that walks by itself, a camera that pans on its own, or a menu cursor that slides in one direction.

A raw axis number can technically reveal this, but it is easy to miss a value sitting at 0.08 instead of 0.00 in a list of figures. Plotting the stick as a dot inside a square makes it immediate: release the stick, and on a healthy controller the dot sits dead center. If the dot rests off center on its own, you are looking at drift, and the tool draws a warning once the resting distance from center crosses a small dead zone, roughly the threshold games themselves ignore.

To judge it fairly, take your hands off the controller completely and set it on a flat surface, because pushing a stick and slowly releasing can leave a brief off-center reading that is not drift. Watch where the dot settles once the stick is truly at rest. A dot that keeps landing away from center, especially in the same direction every time, is the hardware telling you the sensor no longer returns to zero.

A stick can rest correctly at center and still be faulty at the edges. Wear, a cracked gimbal, or a worn potentiometer can stop a stick from reaching its full range in one direction, so pushing all the way gives less than the full signal. The reach reading captures the largest value each axis has hit since you started, so you can prove the stick covers its whole range instead of guessing.

Roll each stick slowly around a complete circle, pressing into the edge the whole way. On a good stick every axis reaches close to -1 at one extreme and 1 at the other, and the dot traces a shape that fills the square. If one direction stops at 0.7 while the opposite reaches 1.0, that side is weak, and in a game it feels like the character turns or accelerates more slowly one way than the other. The same idea applies to triggers: the max reach next to each trigger bar confirms whether it can actually hit a full 1.00 pull, which matters for the throttle in a racing game or a full-strength action bound to trigger depth.

Because reach only ever grows, use the Reset ranges button before testing a different controller or after cleaning a stick, so the new measurement starts from zero rather than carrying over the previous best.

Press each face button, bumper, stick click, and D-pad direction in turn and confirm exactly one tile lights for each. When a controller reports the standard mapping, the numbers line up with a familiar layout: B0 is the bottom face button, A on Xbox or cross on PlayStation, and the numbering runs through the face buttons, bumpers, back and start, the two stick clicks, and the four D-pad directions. The tool lists that key so you can match a tile to the physical button.

Two button faults are worth watching for. If pressing one button lights a different tile, the controller is mismapped, which a remap in software or a controller firmware update usually explains rather than a broken switch. If a tile flickers on and off while you hold the button steady, the switch may be chattering, sending repeated contacts from one press, which is a hardware fault. A D-pad that lights two directions at once when you press one is either a worn contact or a pad that registers diagonals deliberately, so compare it against how it behaves in a game.

For the keys and pointer next to your setup, the Keyboard Tester checks rollover and stuck keys, and the Touchpad Tester maps dead zones and click faults on a trackpad.

It reports only what the browser Gamepad API exposes, and that leaves some things out. Rumble and vibration support is patchy across browsers and controllers, so this tool does not try to test it; a controller that cannot rumble here may still rumble in a game. Motion sensors, gyroscopes, touchpads on the controller itself, light bars, and adaptive trigger resistance are largely invisible to the standard API, so their absence here is not proof they are broken.

It cannot measure input latency in a way that reflects real play, because a browser polling loop sits far from the game engine and the display. It cannot tell a software remap from a hardware fault on its own, which is why a button that lights the wrong tile points you to check your mapping first. And the drift warning is a guide, not a verdict: a stick just inside the threshold can still cause trouble in a sensitive game, and one just outside it may be fine, so treat the dot position as the real evidence.

What it does do is direct and local: it plots each stick so drift and range problems are visible at a glance, draws triggers as the analog inputs they are, records how far every input travels, and confirms the data is live. Nothing about how you play leaves your browser.