Click every button on your mouse in the pad below. This page catches presses that fire twice on their own — the worn switch behind files opening twice and drags that let go halfway.
Click here with every button: left, right, the wheel, and the thumb buttons. Double-click to measure the gap between your two presses.
Clicks recorded: 0
Click each button in the pad above about 15 times. Nothing is judged until there is enough to judge on.
Click each button around 15 times. The bar fills as the sample grows, and no button is called healthy before it is full.
Double-click inside the pad above. This is the gap between your two presses and whether the system turned them into one double click.
The slowest accepted and the fastest rejected gap bracket the double click speed set in your system settings — for most people somewhere near 500 ms.
A mouse that clicks twice on its own is not a settings problem and not your imagination — it is a mechanical fault with a name, a cause and several fixes.
Inside every mouse button sits a switch with a small metal contact that springs back when you let go. Once it has worn, it bounces on release and sends a second press milliseconds later. Your hand made one click; the computer received two. That is what opens files twice, drops drags halfway and selects things you never meant to select.
Wear, mostly. The contact inside a switch is a thin metal leaf under constant load, and it slowly loses its springiness. Dust and skin oil in the housing make it worse, and so does a hard, fast clicking style — which is why gamers meet the fault first. Every switch is rated for a click count, typically 10 to 50 million, and heavy users reach it.
A separate problem with the same symptom is the double click speed set in your operating system. If it is set too fast, deliberate double clicks arrive as two single clicks and folders refuse to open. The slowest accepted and fastest rejected gaps measured above show exactly where your setting sits, so you can move the slider with a number in hand.
In order of effort: claim the warranty if the mouse is still covered, since opening the case usually voids it. Otherwise clean the switch with contact cleaner, or raise the debounce time in the maker's software if your mouse has any. A switch is a cheap soldered part, so a repair shop — or a steady hand — can simply replace it.
Chatter counts as a manufacturing defect for most makers rather than as fair wear, and mice are routinely replaced under warranty because of it. Support will ask what the mouse does; the button name, the number of double fires and the shortest gap in milliseconds are the description they accept.