Double Click Test

A double click test shows whether your mouse sends two clicks when you press the button once. Click the pad above slowly, one press at a time: any two presses of the same button that arrive less than 80 ms apart are flagged as a double click, because a slow, deliberate click cannot produce a gap that short.

How to use the double click test

The test needs no setup. It starts counting the moment you click the pad.

1. Move the cursor onto the pad labelled Click here, one slow click at a time.
2. Click the left button slowly, roughly once per second. The hint under the pad says it plainly: around 50 single clicks is a fair test.
3. Watch the three counters: Clicks, Double clicks and Shortest gap.
4. Repeat with the right and middle buttons. Each button is timed separately.
5. Press Reset to clear everything and start a new run.

While you click, the pad message changes. No double clicks so far means every press has been clean. If a fault is caught, the message switches to a count such as 1 double click detected and the pad border changes colour.

Every press also adds a small chip under the pad, for example "Left button 1012 ms". The number is the time since the previous press of that same button. Flagged presses are highlighted, and the row keeps the most recent 24 clicks so you can see exactly when a fault happened.

What counts as a double click?

The test measures one thing: the gap between two consecutive presses of the same button. If the gap is shorter than the selected threshold, the second press is flagged.

This works because of how you are clicking. At one click per second, every gap should be close to 1000 ms. A gap of 12 ms or 40 ms in the middle of that rhythm is not something your finger did. It is the switch making contact twice.

Shortest gap is the most useful number when the result is borderline. It shows the smallest gap seen across all buttons in the current run, flagged or not. If it sits at several hundred milliseconds, nothing suspicious happened.

Which threshold should you pick?

The Flag clicks faster than selector offers four thresholds: 50, 80, 100 and 150 ms. The default is 80 ms. A change applies to the clicks you make after switching; clicks already counted are not re-judged.

A higher threshold catches more faults but also more false alarms. If you raise it, slow down. The slower you click, the more certain you can be that a flagged click came from the hardware.

Why does a mouse double click?

Most mouse buttons sit on top of a small mechanical micro switch. Inside is a springy metal blade that snaps onto a contact when you press. Metal contacts do not close cleanly. They bounce for a very short time, opening and closing before they settle.

Mouse firmware hides this with debounce: after the first contact, it ignores further changes for a short window. As the switch wears, or the contacts oxidise or collect dirt, the bounce can last longer than the debounce window. The firmware then reports a second press, and your computer sees a double click.

That is why the fault usually appears on the button you use most, shows up after months or years of use, and starts out intermittent. The full list of causes and fixes, including the software ones, is in why is my mouse double clicking.

How to get a reliable result

A switch fault rarely fires on every press, so a single short run can mislead you in both directions. A few habits make the result trustworthy:

• Click slowly. One press per second leaves no doubt about which clicks were yours.
• Do at least 50 clicks per button. For a fault that only shows up now and then, go to 200 or more.
• Vary the press. Try light presses, firm presses, and pressing near the front and the back of the button. Worn switches often fail only at one pressure or position.
• Repeat after the mouse has been in use for a while. Some faults come and go from one session to the next.
• Retest on another computer or USB port if you want to rule out software on your own machine.

One flagged click in 200 is still a real event. A healthy switch does not produce a 20 ms gap during slow clicking, even once. Treat it as an early warning and test again in a few days.

What if the double click only happens while dragging?

Some failing switches behave during short clicks and only let go when you hold the button down. You notice it as files dropped halfway, text selections that end early, or a window that stops following the cursor.

A click test will not always catch that, because each press is too short. Use the mouse drag test instead. It asks you to hold the button while moving a circle into a ring and logs every early release.

What this test can and cannot tell you

The test sees button presses as your browser receives them. That has a few consequences worth knowing:

• It cannot see the raw switch signal. The mouse firmware has already filtered the signal with its own debounce. What you see is the bounce that got through, which is exactly what your games and apps see too.
• Timing is accurate to a few milliseconds, not microseconds. Presses are reported at the mouse's polling interval and browsers limit timer precision. That is more than enough to tell a 30 ms bounce from a 1000 ms click.
• Software clicks count too. A macro, auto-clicker or remapping utility that sends extra clicks will be flagged the same way. Close those tools before testing hardware.
• A clean run is not a guarantee. It tells you the fault did not occur during this run.

What to do if your mouse fails

Start with the steps that cost nothing and cannot damage the mouse.

1. Unplug the mouse, or switch it off and remove the batteries, wait a minute and reconnect it. Then test again.
2. Try a different USB port, and for a wireless mouse, charge it or fit fresh batteries and move the receiver closer.
3. Check the manufacturer's software for a debounce time setting and raise it one step. Not every model has one.
4. Update the mouse firmware and software if an update is available.
5. If the mouse is still under warranty, contact the seller or manufacturer before you open it. A repeatable test result is useful evidence.
6. Out of warranty, the lasting fix is cleaning or replacing the switch, which on most models requires soldering.

The repair guide on why your mouse is double clicking walks through each step in order.

Related tests

If one button is failing, check the rest of the mouse while you are here. The full mouse test lights up every button, including the side buttons, and counts double-click faults for all of them at once. The scroll test checks the wheel for steps that jump backwards, which is the other fault that tends to show up on a well-used mouse.