ByteScope

Gamepad Tester

Plug in a controller, press a button — then measure what your sticks are really doing.

Your files never leave your browser — all processing is local.

Connect a controller and press any button

Browsers hide gamepads until they receive input (a privacy measure). Pair over USB or Bluetooth, then press any button to wake it.

About this tool

Connect a controller over USB or Bluetooth and press any button to wake it (the Gamepad API only reveals a pad after input — the page guides you through this). Every button lights up on a controller diagram as you press it, triggers show their analog 0–1 values, and multiple controllers can be tested side by side.

The stick analysis is the heart of the tool. A live XY scatter plot with trail shows exactly where each stick sits; a circularity test has you roll the stick around its rim to reveal range problems; a magnified center view makes resting offset visible; and the guided drift test — hands off the controller for 10 seconds — measures average and peak deviation and gives a plain verdict like "left stick drifts 3.2%, above the normal range". Stick drift is the defining fault of modern controllers, and measuring it beats guessing.

Rounding it out: a dual-rumble vibration test with separate strong/weak motor sliders, a polling-rate estimate from timestamp deltas (125 Hz wired pads vs 1000 Hz esports pads show up clearly), and the same rapid re-trigger chatter detection used in our keyboard tester. Everything runs locally in your browser — input data never leaves your device.

Frequently asked questions

My controller doesn't show up — what do I do?
Press any button on it first: browsers hide gamepads until they receive input, as a privacy measure. If it still doesn't appear, check that it's paired/connected at the OS level, and try another USB port or re-pairing Bluetooth. Some very old or exotic pads don't implement the standard mapping and may appear with unusual button numbering.
How much stick drift is normal?
At rest, a healthy stick should sit within about 1–2% of center (games hide this inside their dead zones, typically 5–10%). Consistent resting offset beyond ~3–5%, or a stick that wanders while untouched, will be visible in gameplay as unwanted movement — that's the classic worn-potentiometer fault that warrants cleaning, recalibration or repair.
Does the vibration test work with every controller?
It uses the Gamepad API's dual-rumble actuator, which works for most Xbox and PlayStation pads in Chromium browsers. Some browsers and some pads (and most Bluetooth connections on macOS) don't expose rumble — the tool tells you when the actuator isn't available rather than failing silently.
Can I use a Switch Pro controller or Joy-Cons?
Yes for testing: they pair over Bluetooth and expose the standard mapping in most browsers. Note the browser can only read the controller — it cannot turn it into a system-wide virtual gamepad for other PC games; that requires a driver-level tool like BetterJoy or Steam Input.
What does the polling rate number mean?
How often your controller reports its state, estimated from the timestamps between updates. 125 Hz (8 ms) is the common baseline, high-end wired pads reach 1000 Hz (1 ms). Lower isn't broken — but if a "1000 Hz" pad measures 125 Hz, check its wired connection and mode.