How to test a controller
- Connect the controller to your computer or phone with a USB cable or over Bluetooth (pairing steps below).
- Press any button. Browsers hide controllers from a page until a button is pressed, so nothing appears before that. The status box turns green and a panel for the controller appears.
- Press every button once. On the drawing, a button lights up blue while you hold it and stays green once it has worked; Buttons tested counts them. A button that never turns green did not reach the browser.
- Squeeze each trigger slowly. LT/L2 and RT/R2 are analog: the value should rise smoothly from 0.00 to 1.00, and the bar on the drawing fills with it.
- Move both sticks to every edge, press them in (L3/R3), then let go and read Offset from center — that resting value is the stick drift.
- Press Both motors, Strong motor and Weak motor to check vibration, where your browser supports it.
Several controllers can be tested at once: each gets its own panel, numbered in the order the browser found them.
Reading the results
Controllers that the browser recognizes use the standard mapping, which names buttons by their position, not by the letters printed on them. Button 0 is always the bottom face button — A on Xbox, ✕ on PlayStation, B on a Nintendo Switch Pro Controller — and button 3 the top one. The list shows Xbox and PlayStation names side by side, and the drawing switches to the symbols of the brand it detects.
| Index | Xbox | PlayStation |
|---|---|---|
| 0 · 1 · 2 · 3 | A · B · X · Y | ✕ · ○ · □ · △ |
| 4 · 5 | LB · RB | L1 · R1 |
| 6 · 7 (analog) | LT · RT | L2 · R2 |
| 8 · 9 | View · Menu | Share or Create · Options |
| 10 · 11 | Left and right stick press | L3 · R3 |
| 12–15 | D-pad up, down, left, right | |
| 16 | Xbox button | PS button |
Each stick has two axes from −1 to 1: X is negative to the left, and Y is negative up (screen direction). A controller with a non-standard mapping still works here, but the browser numbers its buttons and axes in whatever order the device reports them, so the names are replaced by plain numbers.
Stick drift and the dead zone
A stick reports its position as an X and a Y value. Released, a healthy stick springs back close to 0, 0. Stick drift is when it doesn’t: worn sensors, dirt or a weak spring leave it reading an offset, and the character or camera creeps without your thumb touching it. The tester turns X and Y into one number, the distance from the center: offset = √(X² + Y²).
Games ignore a small circle around the center, the dead zone, so a little resting offset never moves anything. The green circle in each stick view is that zone; set its size with the slider (10 % by default) to match the dead zone in your game’s settings.
Example
You let go of the left stick and it rests at X 0.06, Y −0.08. The offset is √(0.06² + 0.08²) = √0.01 = 0.10, so 10 %. With a 10 % dead zone that sits right on the edge: the slightest extra nudge moves your character. A stick that rests at X 0.03, Y 0.04 has an offset of 5 % and is fine. If a stick rests outside the dead zone, flick it a few times, check again, and compare it with the other stick — one stick much worse than the other points to wear rather than a calibration setting.
To check the stick’s range, turn it slowly around its outer edge: the faint line traces the last positions. It should reach close to the rim all the way round; a flat side or a gap shows a direction where the stick can’t reach full deflection.
Connecting your controller
- Xbox controllers work over USB on Windows. Models with Bluetooth pair by holding the small pair button on top until the Xbox button flashes, then choosing the controller in your device’s Bluetooth settings.
- PlayStation DualShock 4 and DualSense: connect a USB cable, or hold Share (Create on DualSense) and the PS button together until the light flashes, then pair over Bluetooth.
- Nintendo Switch Pro Controller: hold the small sync button on top until the lights run, then pair over Bluetooth, or use a USB cable.
- Android: pair the controller in Bluetooth settings (or use a USB-C adapter) and open this page in Chrome.
- iPhone and iPad: pair in Settings › Bluetooth and open this page in Safari.
- Steam open on your PC? Steam Input can take over controllers and pass them to other programs as a different device. If the tester shows nothing or the wrong buttons, close Steam and try again.
Browser support and limits
- Chrome, Edge, Opera, Firefox and Safari all support the Gamepad API. Chrome and Edge recognize the most controllers with the standard mapping.
- Vibration needs the browser to offer it: Chrome and Edge do for most controllers, Safari on a Mac from version 16.4. Firefox and Safari on iPhone and iPad have no vibration for web pages, so the tester says so instead of showing the buttons. Trigger motors (the rumble in Xbox triggers) appear only where the browser offers them — Chrome and Edge from version 126. The gyroscope, the light bar and the DualSense adaptive triggers aren’t available to web pages.
- Readings update as often as your screen refreshes, usually 60 times a second. The tester can’t measure the controller’s USB polling rate or input lag.
- The tester only reads what the browser receives. A button that works here but not in a game points to the game’s or Steam’s settings, not the controller.
Testing other gear? Check every key with the keyboard tester, mouse buttons and the scroll wheel with the mouse test, and your reflexes with the reaction time test.
Frequently asked questions
Why does the gamepad tester not detect my controller?
Press a button on the controller first: browsers reveal a controller to a page only after a button press. If nothing appears, try another USB cable or port (some cables only charge), re-pair it over Bluetooth, close Steam in case it has taken over the controller, and try Chrome or Edge.
How do I check my controller for stick drift?
Let go of both sticks and read Offset from center under each stick view. A healthy stick rests within a few percent of the center. If a stick rests outside the dead zone you use in games, the character or camera can move by itself — that is drift.
What dead zone should I use?
The smallest one that keeps your sticks still at rest. Read each stick’s resting offset here and pick a game dead zone slightly larger than it. A bigger dead zone hides drift but makes small aiming movements less precise.
Does it work with PS5, PS4, Xbox and Switch controllers?
Yes, connected to a computer or phone by USB or Bluetooth. The browser names buttons by position, so the bottom face button is button 0 on every controller: A on Xbox, ✕ on PlayStation and B on a Switch Pro Controller.
Why does the vibration test not work?
Web pages can make a controller vibrate only in browsers that support it — Chrome, Edge, and Safari on a Mac from version 16.4. Firefox and Safari on iPhone and iPad don’t. Some controllers connected over Bluetooth also ignore the command.
Is my controller input recorded?
No. The readings are shown on this page only. Nothing is stored or sent to a server, and nothing remains after you close the page.
Last updated: October 19, 2026