How the gamepad tester works
Connect the controller with a cable or over Bluetooth and press any button: browsers show a controller only after its first button press, so that pages cannot list your devices unasked. The page then shows the controller's name, its layout, the number of buttons and axes, every button lighting up as you press it, and a bar for each axis. The axes are the sticks: each stick has two, one horizontal and one vertical, with values from -1 to 1 and 0 in the middle. You can test several controllers at once.
Standard layout
"Standard" means the browser maps the controller to the common layout, the same for Xbox and PlayStation controllers:
- 0-3: the face buttons (A, B, X, Y on Xbox; cross, circle, square, triangle on PlayStation)
- 4 and 5: LB and RB (L1 and R1)
- 6 and 7: the triggers LT and RT (L2 and R2)
- 8 and 9: the two small buttons in the middle (View and Menu on Xbox)
- 10 and 11: pressing the left and the right stick
- 12-15: the D-pad: up, down, left, right
- 16: the Xbox or PS button, if the browser passes it on
"Controller's own" means the browser does not recognise the model and numbers the buttons in the controller's own order. Everything still works, but the numbers differ from the list above.
Stick drift and other faults
Leave the sticks alone and watch the axis values. Values that stay near 0.00, such as 0.01 or 0.02, are normal, and games ignore them with a so-called dead zone. A value that stays clearly away from zero, or a bar that moves on its own, means stick drift, a common fault of worn sticks. Also check that every button lights up and goes dark again. Test vibration appears when the browser can control the motors, which is the case in Chrome and Edge.
Checking a used controller
Before you buy a used controller, or when one starts to misbehave, press every button once and watch it light up; move each stick slowly in a full circle and check that both bars reach -1 and 1 without jumps; press each stick down and pull both triggers; try every direction of the D-pad. Then leave the controller on the table for a minute and check that the axis values stay near zero.
Questions
Why is my controller not shown?
Press any button after connecting it. If it still does not appear, try another USB port or cable, or pair it again over Bluetooth.
Which controllers work?
Most USB and Bluetooth controllers, including Xbox and PlayStation ones, in current versions of Chrome, Edge, Firefox and Safari. Controllers the browser recognises get the standard layout.
How do I know if a stick drifts?
Release the stick and watch its two axes. If either value stays clearly away from 0.00 or keeps changing, the stick drifts.
Why is the vibration button missing?
The browser has no access to the controller's motors. Vibration works in Chrome and Edge.
What do the axis values mean?
They show the position of a stick from -1 to 1. On the horizontal axis -1 is fully left and 1 fully right; on the vertical axis -1 is usually fully up and 1 fully down.
Why are the triggers shown as buttons?
In the standard layout the triggers are buttons 6 and 7 with a value between 0 and 1. The page lights them up once you press them about a tenth of the way.
Does the test change anything on my controller?
No. The page only reads the buttons and sticks and does not change any settings.