Mouse Drag Test
Does your mouse let go while you drag? Hold a button and draw big loops: every split-second release is caught, timed and marked on your path. Includes a drag-and-drop file check. Free, runs in your browser.
Red dot = a release and re-press within 300 ms (a drop)
On touch screens only a single finger is tested, and the button choice is ignored. The browser sees what your operating system reports, so a mouse with long firmware debounce may hide very short drops.
How the mouse drag test works
What counts as a drop
Every press and release is stamped with a high-resolution timer. If the button goes up and comes back down within 300 ms, the test logs a drop, puts a red dot where it happened, and breaks the line. Letting go without another press inside that window is not a drop, including when the timer ends or you press Finish. Gaps under 80 ms are called out as faster than a finger can let go and press again. Longer gaps ask you to hold firmly and run it again. With no drops, the result is called healthy only after at least 3 seconds of holding in total.
Why drags fail
A mouse button is a small metal spring contact. After millions of clicks the metal fatigues and oxidises, so under steady pressure it can flicker open for a few milliseconds. The firmware is supposed to filter this with debounce, a short window that ignores bounce, but a cheap or worn switch bounces for longer than the window covers.
In real use this looks like files dropping halfway into the wrong folder, windows letting go mid-move, text selections cutting short, or a game releasing your aim or a charged shot. Some mice sold as rated for 50 million clicks start doing it within a year.
Fixes worth trying
- Raise the debounce time in the mouse software, if it has the setting. 8 to 12 ms often hides early wear.
- Clean the switch: compressed air around the button, and many rapid clicks to scrub the contacts.
- Swap the switch. Omron, Kailh and optical replacements are cheap if you can solder.
- Claim the warranty. Record a run of this test showing the drops as evidence.
Drag drops vs double clicking
They are the same fault seen from two sides. A worn switch that bounces when pressed sends two clicks instead of one. The same switch flickering while held makes a drag let go. If this test finds drops, the double click test will usually find doubles on the same button too.
Related tools
Check every button and the cursor with the mouse tester, catch a cursor that moves on its own with the mouse drift test, test the wheel with the mouse scroll wheel test, and look for chattering clicks with the double click test.
Frequently asked questions
What counts as a drop in the hold and drag test?
A drop is the chosen button going up and coming back down within 300 ms. The pad marks that release with a red dot and stores the gap. Letting go on its own does not count, including when the timer ends or you press Finish in Free mode. Pressing again after more than 300 ms is a new press, not a drop. A gap under 80 ms is called out as faster than a finger can let go and press again. Longer gaps tell you to hold firmly and run it again. A run with no drops is called healthy only when the button was down for at least 3 seconds in total.
Which buttons does the test listen to?
Pick left, middle, or right. Only that button adds presses and drops. While a drag is held, another button or another finger does not add a press or a drop. Touch and pen use the primary contact, and the button choice is ignored.
How do I run the hold and drag test?
Choose Hold & drag, then a button, then 5, 10, or 20 seconds, or Free. Press and hold on the pad and drag in big loops. A timed run starts on that first press and stops when the time is up. In Free, press Finish when you are done. Reset clears the path, the timer, and the drop count. Changing the button or the length starts a fresh pad.
How does the drag and drop check work?
Choose Drag & drop. There are 10 rounds. Hold the chosen button on the file and drag it into the folder. The folder moves each round. Letting go while the pointer is over the folder counts as dropped in. Letting go anywhere else counts as a fail, after a 300 ms wait. Releasing on the folder on purpose is not a fail.
What is a switch drop, and how is it different from a fail?
A switch drop is the file being let go and grabbed again within 300 ms during the same round. That number is separate from fails. A fail is a round that is still outside the folder when that wait ends. A quick re-grab is not a fail, and reaching the folder still counts as dropped in even if a switch drop happened on the way. Fails is how many rounds missed the folder. When all 10 rounds end with at least one miss, the summary shows that count as a percent of rounds played, rounded to the nearest whole number. There is no other cutoff.
What do the numbers on the pad mean?
In Hold & drag, Time left (Elapsed in Free) is the run clock, Held for is the total time the button has been down, Distance is the path in pixels, Drops is the 300 ms release-and-press count, and Longest hold is the longest unbroken press. In Drag & drop, Attempt is the round out of 10, Dropped in is rounds that landed on the folder, Fails is rounds that missed it, and Switch drops is the quick let-go-and-grab count.
Why can a bad switch still show zero drops?
The page only counts breaks the browser actually receives. Mouse firmware can swallow a very short opening with debounce, so it never shows up here. If the fault comes and goes, run the loops more than once. This test does not measure polling rate, cursor drift, or the scroll wheel.