Test your mouse in the browser, no install needed
A mouse is the one peripheral you stop noticing until it misbehaves. A button that fires twice on a single press, a scroll wheel that jumps the wrong way, a cursor that stutters across the screen — these are small faults that quietly ruin a click-drag, a spreadsheet selection or a headshot. This mouse test reads the raw input events your browser already receives and shows them back to you, so you can see exactly what your mouse is reporting before you decide whether to clean it, repair it, or replace it. It runs locally, needs no permission prompt, and works the same on Windows, macOS and Linux.
There are a few moments when a quick check pays off. The first is troubleshooting a mouse that feels off but you can't quite prove it. The second is buying used gear — a worn switch is far easier to catch in two minutes of clicking than to argue about afterward. The third is verifying a brand-new or freshly repaired mouse actually does what its spec sheet promises across every button.
What the tool checks
The test watches every part of the mouse the browser can see. It registers left, right and middle clicks, lighting up each button as you press it, so a dead button shows itself immediately by simply never responding. It tracks the scroll wheel in both directions, including the middle-button press that many wheels double as, which catches a wheel that skips steps or scrolls backward. It follows movement, drawing the cursor's path so you can spot a pointer that stutters, jumps, or drifts while your hand is still. Side buttons, where your mouse has them, register too.
The headline feature for most people is the double-click check. The browser timestamps every press, and the tool measures the gap between two clicks on the same button. A real human double-click leaves a comfortable gap; a worn switch fires a phantom second click within a handful of milliseconds — typically under about 80 ms, faster than any finger can move. When you press once and the tool logs two clicks too close together, you've found the fault, not imagined it.
Why a mouse double-clicks on a single press
This is the most common mouse failure, and it almost always comes down to the microswitch. Inside each button is a tiny metal leaf spring that snaps against a contact when you press. Over millions of clicks that spring loses tension, and instead of one clean snap it bounces — making and breaking contact in quick succession. The computer reads that bounce as a second click. The result is the maddening pattern of single presses that open two files, drag-and-drops that drop the moment you start, and selections that collapse on their own.
It's worth being clear that this is wear, not software gone wrong. Reinstalling drivers won't bring a fatigued spring back, and the problem only worsens with time. Knowing that distinction saves you from chasing settings when the cure is physical.
Fixes, from easy to involved
Start with the cheap options. A can of compressed air or a little isopropyl alcohol worked into the button can clear grit and oxidation from the contacts, and on a lightly worn switch that sometimes buys you months. Lowering the polling rate in your mouse's software, or enabling a click-debounce setting where the manufacturer offers one, adds a tiny delay that filters out the phantom click — a useful band-aid, though one a worsening switch will eventually out-wait.
The reliable fix is replacing the microswitch. The worn part is a standard component — popular choices include Omron and Kailh switches rated for tens of millions of clicks — and on many mice it's three solder pins to remove and replace. If a soldering iron isn't your thing, some models such as the Logitech G304 and G305 sell pre-assembled switch boards you can swap with a screwdriver, and a local repair shop will do the job for roughly the price of a couple of coffees rather than a whole new mouse. When you're done, run this test again and confirm the double-click is gone before you trust it.
While you're here, the cursor-movement view doubles as a smoothness check: if the path looks ragged or laggy, suspect a low battery on a wireless mouse, a clogged optical sensor, or a worn mouse-feet-and-pad combo before blaming the mouse itself. For more peripheral checks see all device tests, and if you want to measure your own click timing rather than the hardware's, try the reaction time test.
Frequently asked questions
How does the double-click test detect a faulty mouse?
The browser records the exact time of every click. The test measures the gap between two presses on the same button, and a gap under roughly 80 milliseconds is faster than a human can click, so it flags a phantom click from a worn switch.
Why does my mouse double-click on a single press?
Almost always a worn microswitch. The tiny metal spring inside the button loses tension over millions of clicks and bounces when pressed, making contact twice. The computer reads that bounce as a second click. It is physical wear, not a software bug.
Can I fix a double-clicking mouse without replacing parts?
Sometimes, temporarily. Compressed air or isopropyl alcohol can clear grit from the contacts, and a debounce or polling-rate setting can mask the phantom click. These help a lightly worn switch, but a badly fatigued one needs the microswitch replaced.
Does the mouse test need permission or an install?
No. It reads the click, scroll and movement events the browser already passes to any web page, so there is no permission prompt and nothing to download. It runs entirely in the browser and works on Windows, macOS and Linux.
What does the scroll and movement check show?
The scroll check confirms the wheel reports both directions and the middle-button press, catching a wheel that skips steps or scrolls backward. The movement check draws the cursor path so you can spot stutter, jumps or drift while your hand is still.
Is replacing a mouse switch worth it?
Often yes. The switch is a cheap standard part rated for tens of millions of clicks, and on many mice it is a quick swap or a low-cost repair-shop job. Some models offer screwdriver-only switch boards, so a worn button rarely means buying a whole new mouse.