I built a browser-based controller tester with the Gamepad API — and a stick-drift verdict

GanNaSong — Mon, 22 Jun 2026 07:52:26 +0000

A quick one I built recently. Stick drift — when an analog stick reports input while it's sitting centred — is the most common way a game controller dies, and it turns out you can detect it from a web page with no native code at all, thanks to the Gamepad API. So I made a free tool that does exactly that and returns a plain pass/fail verdict instead of a wall of raw numbers.

What stick drift actually is

An analog stick reports its position as two numbers, X and Y, each running from roughly -1.0 to +1.0. At rest, both should sit at 0.0. Stick drift means that at rest the stick reports a non-zero value — say X = 0.18 — so the game thinks you're pushing the stick when your thumb is nowhere near it. The cause is usually a worn or contaminated potentiometer inside the stick module: dust, or just mechanical wear after a few thousand hours.

The thing most "how to test" guides get wrong: a tiny non-zero reading is normal. Every analog stick has a little electrical noise. The question isn't "is the resting value exactly zero" — it never is — it's "is the resting value large enough that the game will register it as input." That threshold is what separates a healthy stick from a drifting one.

The Gamepad API part

Modern browsers expose connected gamepads through navigator.getGamepads(), so any page can read buttons and stick axes directly — no driver, no download, and the input never leaves the machine. I used that to build a tool that reads the resting axis values and turns them into a verdict: test your controller for stick drift. Connect over USB or Bluetooth, leave both sticks untouched for a few seconds, and it tells you whether the resting drift is within a healthy range or past the point where it'll affect gameplay.

If you'd rather read the raw values yourself, the main controller tester shows live X/Y for both sticks, every button, trigger travel, and rumble.

Reading the result

Resting value under ~0.05–0.08: healthy. That's normal noise; leave it alone.
Resting value around 0.1–0.2: early drift. Often recoverable — a contact-cleaner flush of the stick module fixes a lot of these.
Resting value above ~0.2, or a stick that won't return to centre: the module is worn. Cleaning may buy time, but a module replacement is the real fix.

What to do next

If the test says the stick is healthy but a game still misbehaves, the problem is almost certainly a deadzone or sensitivity setting in that game, not the hardware. If it confirms drift, decide between a cleaning attempt and a module swap based on how far past the threshold you are.

Works with Xbox, PlayStation (DualSense / DualShock) and Switch Pro controllers. Free and entirely client-side — controllertester.co.

DEV Community: GanNaSong

I built a browser-based controller tester with the Gamepad API — and a stick-drift verdict

What stick drift actually is

The Gamepad API part

Reading the result

What to do next