Controller not detected in the browser
A pad that charges, pairs and works in games can still be invisible to a web page. Almost always it is one of six things.
Press a button first
For privacy reasons, browsers refuse to reveal a connected gamepad until it sends an input. This is the single most common reason a tester shows nothing.
Click on the page so the tab has focus, then press a face button or move a stick. Controller data never reaches a background tab.
Cables, ports and pairing
Many spare cables carry power only. Swap to one you know transfers data, and plug into a port on the machine rather than through an unpowered hub.
For Bluetooth, remove the existing pairing and pair again from scratch. A half-broken pairing often still charges and still shows as connected.
Software that steals the controller
Steam Input, DS4Windows, the Xbox Accessories app and various remapping utilities can take exclusive control of a pad, leaving nothing for the browser. Close them and reload.
If the pad appears in Chrome or Edge but not elsewhere, the browser is the limitation rather than your hardware — support for optional features differs considerably.
Ready to check your own controller?
Open the gamepad tester