Window: gamepadconnected event
The gamepadconnected event is fired when the browser detects that a gamepad has been connected or the first time a button/axis of the gamepad is used.
The event will not fire if disallowed by the document's gamepad Feature Policy.
This event is not cancelable and does not bubble.
Examples
To be informed when a gamepad is connected, you can add a handler to the window using addEventListener(), like this:
window.addEventListener('gamepadconnected', event => {
    // All buttons and axes values can be accessed through
    const gamepad = event.gamepad;
});
Alternatively, you can use the window.ongamepadconnected event handler property to establish a handler for the gamepadconnected event:
window.ongamepadconnected = event => {
    // All buttons and axes values can be accessed through
    const gamepad = event.gamepad;
};
Specifications
| Specification | 
|---|
| Gamepad # event-gamepadconnected | 
Browser compatibility
BCD tables only load in the browser