How the vibration test works
Most controllers have two rumble motors, each spinning an off-centre weight:
- the strong motor, in the left grip, with a heavy weight for deep, slow rumble;
- the weak motor, in the right grip, with a light weight for fast, high-pitched buzz.
The test drives them through the Gamepad API’s vibration interface. Set each motor’s intensity from 0 to 100 %, choose a duration up to 5 seconds and a pattern, then start. The two bars show what is being sent to each motor at every moment.
- Steady holds the chosen intensity for the whole duration.
- Pulses alternate 120 ms on and 120 ms off, like a heartbeat. A motor that starts late or keeps spinning between pulses is worn.
- Ramp climbs from one eighth to the chosen intensity in eight steps. A healthy motor starts within the first two or three steps.
The Strong motor only and Weak motor only buttons play one motor alone. That is the quickest way to find a dead one: games always mix both.
Reading the result
| What you feel | What it means |
|---|---|
| Both motors run, each one distinct | Healthy. |
| One motor stays silent | Dead motor or broken wire. The other one is often working harder in games, which hides it. |
| A motor only starts above 50 % | Worn motor or weak battery. Test again plugged in. |
| Rattling or grinding noise | The weight hits the shell or the motor is loose. |
| The controller disconnects when it vibrates | Battery too weak to supply the motors. Very common on Xbox controllers with old AA cells. |
Xbox trigger motors
Xbox One and Series controllers have two extra motors in the triggers. When your browser reports them (Chrome and Edge on some Windows setups), a Trigger motors button appears. The strong motor setting drives the left trigger, the weak one drives the right.
Limits
Only Chrome, Edge and other Chromium browsers let a page drive rumble, on desktop and on Android. The browser limits each effect to 5 seconds. The test cannot measure motor speed or current, only send commands: the verdict is your hand. The DualSense haptics and adaptive triggers, and the Switch Pro HD rumble, are only partly or not reached. To check buttons and sticks, use the controller tester or the stick drift test.
Frequently asked questions
Why does the vibration test not work in Firefox or Safari?
Web pages can only drive rumble motors through an interface that Chrome and Edge support (and other Chromium browsers such as Opera or Brave). Firefox and Safari do not give pages access to it, so the test tells you to switch browser.
My browser is Chrome but nothing vibrates. Why?
Some controllers do not expose their motors to the browser, mostly third-party ones and some Bluetooth connections. Plug the controller in with a USB cable and reload. Also check that the controller is not in a power-saving mode and that Steam is not taking it over.
Which motor is the strong one?
The strong motor sits in the left grip: a heavy weight that gives a deep rumble. The weak motor sits in the right grip: a light weight that gives a fast buzz. Games use both together, so a dead one is easy to miss.
Does it work with the PS5 DualSense?
Partly. The DualSense has haptic actuators instead of classic motors. Chrome and Edge drive them as if they were two rumble motors, which works but feels cruder than in PS5 games. Adaptive triggers cannot be tested in a browser.
How long can a vibration last?
Up to 5 seconds per run, a limit set by the browser. Use the ramp pattern to hear how the motor behaves from low to full power.
Updated October 26, 2026