Mouse Test
Find out whether your mouse is registering two clicks for one press - measured, not guessed.
Double-click fault test
Click the pad below thirty times or so, at a normal pace, with the button you are worried about. One press should give one click.
Buttons
Press each button in turn. Back and forward appear only if your mouse has them.
Scroll wheel
Scroll over this box, in both directions.
Tracking and report rate
Move the pointer across this box, steadily, for a couple of seconds. The trail should be smooth and continuous — gaps or jumps suggest a sensor problem, a dirty surface, or a wireless connection dropping frames.
The report rate above is a floor, not the mouse's polling rate. Browsers batch pointer events to the display's refresh, so a 1000 Hz mouse on a 60 Hz screen commonly reads as about 60 Hz here. Where the browser exposes the batched-up events this page unpacks them and the figure gets much closer to the truth; where it does not, the number is only ever a lower bound. No web page can measure polling rate properly — a tool that claims otherwise is reporting your monitor.
What this tool does
Click the pad about thirty times at a normal pace. If your mouse is producing extra clicks, the gaps between them will be under about 40 milliseconds - faster than anyone can deliberately click - and the tool will say so, name the button, and show you the measurements.
Records the time of every button press and reports any pair closer together than a person could physically produce, which is the signature of a worn switch.
Also checks every button, both scroll directions, and pointer tracking.
How to use it
- Click the pad about thirty times at your normal pace, with the button you are worried about. The progress bar shows when the sample is big enough to conclude from.
- Read the verdict. Gaps drawn in the red band are faults, not clicks you made.
- Press each button in turn, scroll the wheel both ways, and move the pointer across the tracking box.
- Watch the coverage chips at the top - a mouse is only cleared once all four have lit up.
Why use this tester
A mouse that double-clicks on a single press is a common failure of worn switches and is hard to prove by feel. Timing every press shows whether the pairs are too close for a human.
Why we built it
We built the mouse test to lead with the double-click fault test, because that is why most people arrive. Measure sensitivity with the mouse DPI test and click speed with the CPS test.
Related tools worth a look: the Gamepad Tester and the Reaction Time Test.
Who this tool is for
- Gamers and office users with a double-click fault
- People buying or returning a mouse
- Technicians diagnosing a device
When to use it
- Diagnosing double-clicking or unreliable buttons.
- Testing a second-hand mouse.
- Checking scroll and side buttons.
- Documenting a fault for a warranty claim.
What the double-click fault actually is
It has a name, a cause, and a measurable signature.
This page leads with the double-click fault test because that is what almost everyone is here for. A mouse that has started registering two clicks for one press is the reason people search for a mouse tester at all, and most testers make you infer the fault yourself from a grid of squares lighting up. Naming the fault, measuring it and reporting it is a different job from showing you that a button works.
A mouse button is a mechanical switch, and mechanical switches do not close cleanly. When the contacts meet they bounce apart and back together several times over a few hundred microseconds. Left alone that would register as a burst of clicks, so every mouse contains firmware that ignores further changes for a short window after the first - debouncing.
As a switch wears, the contacts oxidise and lose tension, and the bouncing lasts longer. Eventually it outlasts the debounce window, and the firmware sees the bounce as a genuine second press. One press, two clicks. That is switch chatter, and it is by far the most common way a mouse fails.
The useful part is that it has a signature you can measure. A deliberate double click from a person is roughly 80 to 500 milliseconds apart. Chatter is typically under 40, often under 10. Nobody can click twice in 8 milliseconds, so a gap that short did not come from your hand.
| Gap | What it is |
|---|---|
| Under 20 ms | Switch chatter. Not physically producible by hand. |
| 20 to 40 ms | Almost certainly chatter, especially if it repeats. |
| 40 to 80 ms | Very fast, but a determined person can manage it. |
| 80 to 500 ms | A normal deliberate double click. |
| Over 500 ms | Two separate clicks. |
A worn switch does not recover. It gets worse, and usually quite quickly once it starts.
Why this listens on mousedown
Browsers offer several click-related events, and which one a test uses decides whether it can see the fault at all.
The click event is synthesised: the browser waits for a complete press and release on the same element, then fires once. That synthesis is exactly the layer at which a chattering switch can be smoothed away, because a bounce may not produce a well-formed press-and-release pair.
The dblclick event is worse - it depends on the operating system's own double-click interval, so it reports the system's interpretation rather than what the hardware sent.
The mousedown event fires once per button-down, as close to the raw signal as a web page can get. That is what this tool records, which is why it can see a fault that ordinary use only shows as an occasional annoyance.
If it is failing
A confirmed chattering switch has three practical outcomes.
The switch can be replaced. They are standard parts costing very little, and swapping one is a straightforward soldering job if you have the tools and the confidence. Many mice are held together by screws hidden under the feet.
Some people report success cleaning the switch by opening its housing and burnishing the contacts. It sometimes buys a few months. It is fiddly, it voids any warranty, and it does not undo the loss of contact tension that caused the problem.
Otherwise it is a new mouse. If the one that failed is still in warranty, chatter is a hardware fault and worth claiming for - a saved copy of these results, showing gaps well below human reaction, is a more concrete report than "it double clicks sometimes".
One thing worth ruling out first: a few applications and some mouse utilities implement their own double-click behaviour, and a badly configured macro or a "double click" button assignment can look identical. If the fault appears in one program only, it is software.
The other tests
The button panel lights up as each button is pressed and marks any that register a fault. Back and forward buttons only appear once they have been pressed, because there is no way for a page to know whether a mouse has them.
The wheel box counts each direction separately. A wheel that scrolls up reliably and down erratically points at the encoder inside it rather than at a switch.
The tracking box draws a trail as you move. It should be a continuous line. Gaps or sudden jumps suggest a dirty sensor, an unsuitable surface such as glass or a strongly patterned mousepad, or a wireless connection dropping reports.
What you give it, and what you get back
| Item | Details |
|---|---|
| Input | Click every button, scroll and move the pointer. |
| Output | Timings of presses and a flag for impossible double presses. |
| Checks | Buttons, scroll direction and tracking. |
Issues you may run into
| What you see | Why it happens | What to do |
|---|---|---|
| Fault not detected | A browser sees only events the OS passes on. | Test in more than one app. |
| Polling rate missing | Browsers coalesce mouse events. | Use manufacturer software. |
| Side buttons do nothing | The OS or browser may use them for navigation. | Check the driver settings. |
Assumptions and limitations
- A browser cannot see the raw USB report stream, only the events the operating system passes on. A fault this tool cannot see may still exist.
- Polling rate cannot be measured meaningfully, since browsers throttle and coalesce mouse events.
- Back and forward buttons are handled inconsistently across browsers and may not register at all.
- Some mouse utilities and macro software intercept buttons before the browser sees them, which can mask or imitate a fault.
- This tests the mouse as your system reports it. A fault appearing in one application only is software, not the mouse.
- Not a substitute for testing on a second computer, which is the definitive way to separate a hardware fault from a driver problem.
Frequently asked questions
Why does my mouse double click when I click once?
The switch under the button has worn. Its contacts bounce for longer than they used to, and the mouse firmware can no longer tell the bounce from a second press. It is called switch chatter and it is the most common way a mouse fails.
What is switch chatter?
The contacts inside a mechanical switch bounce apart and back together when they meet. Firmware normally ignores that for a few milliseconds. As the switch ages, the bouncing outlasts that window and gets reported as a real second click.
How do I test for a double-click fault?
Click about thirty times at a normal pace and look at the gaps. Anything under about 40 milliseconds was not produced by your hand - nobody can click twice that fast. This tool measures those gaps and marks them.
Can a double-clicking mouse be fixed?
Yes, by replacing the switch, which is a cheap standard part but needs soldering. Cleaning the contacts sometimes buys a few months. Neither restores the lost contact tension, so the fault tends to return. If it is in warranty, claim - chatter is a hardware fault.
Why does this use mousedown instead of click?
A click event is synthesised from a complete press and release, and that synthesis can smooth a chattering switch out of view. The dblclick event reflects your system's double-click setting rather than the hardware. mousedown is as close to the raw signal as a web page gets.
What counts as a normal gap between clicks?
A deliberate double click is roughly 80 to 500 milliseconds. Below about 40 is faster than a person can produce on purpose. Below 20 is not physically possible by hand at all.
Why do my back and forward buttons not register?
Browsers handle the extra mouse buttons inconsistently, and some map them to page navigation before a page can see them. Their absence here is not evidence that they are broken.