Free Mouse Buttons & Scroll Test
Test mouse buttons, scroll deltas, double clicks and pointer position in a local pad. Reset counters and inspect browser-reported input without signup.
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How to use the mouse buttons & scroll test
Test mouse buttons, scroll deltas, double clicks and pointer position in a local pad. Reset counters and inspect browser-reported input without signup.
- Place your pointer inside the mouse test pad.
- Click left, middle, right or side buttons and inspect the counters.
- Move, double-click and scroll horizontally or vertically to inspect input values.
- Use Reset mouse test to clear counters before another comparison.
When a mouse test is worth running
A mouse can fail slowly. A left button may start registering double clicks, a wheel may skip, or a side button may stop working after a driver update. This test gives you a neutral place to click, scroll and move so you can see what the browser actually receives.
It helps gamers checking a new mouse before the return window closes, office workers who suspect a faulty button, and IT staff who need a quick check on a shared computer without installing software. It is also useful after remapping buttons in vendor software, to confirm the new mapping reaches the browser.
Worked example: checking for a double-click fault
Press Reset mouse test, then click the left button slowly ten times inside the pad, waiting about a second between clicks. A healthy button should show Left: 10 and Double clicks: 0. If the Left counter shows 13 and Double clicks shows 3, the switch is likely sending extra presses, which is a common sign of a worn switch.
Next, hold the left button and keep holding it while you press the right button. The Held button bitmask should read 3. The browser adds 1 for left, 2 for right, 4 for middle, 8 for back and 16 for forward, so holding left and middle together reads 5. A release brings the mask back toward 0.
Finally, roll the wheel down five notches. Scroll Y grows by the amount the browser reports per notch, and the Units line tells you whether those values are pixels, lines or pages.
Understanding the readouts
The five counters map to the standard browser button numbers: 0 for left, 1 for middle, 2 for right, 3 for back and 4 for forward. A counter increases when the browser reports a new press inside the pad. Position shows the pointer location in CSS pixels from the top-left corner of the pad, so it will change with page zoom and display scaling.
Scroll X and Scroll Y are running totals of the wheel deltas. A positive Y value means scrolling down, and X changes when you tilt the wheel or use horizontal scrolling. The right-click menu and middle-click actions are suppressed inside the pad so they do not interrupt the test.
Common mistakes to avoid
Do not compare scroll totals between two different computers and assume one mouse is faulty. The step size depends on the browser, the operating system and settings such as smooth scrolling. Compare the same mouse on the same setup instead.
Remember that pressing a second button while another is held is reported as a change to the held buttons, not always as a fresh press. Check chorded presses with the bitmask rather than the counters. Also keep the pointer inside the pad, because clicks outside it are not counted.
Useful tips and limitations
- Some side buttons can trigger browser navigation and may be intercepted by the browser.
- Scroll delta units can be pixels, lines or pages depending on the browser and device.
- Test one button at a time after a reset, so a stray count from another button does not hide a fault.
- If a side button opens the previous page, check it in the bitmask while holding it down inside the pad.
Common questions
Can the mouse checker measure exact physical DPI?
No. Browser pointer coordinates can be affected by operating-system acceleration and scaling, so this test does not claim physical DPI.
Why do mouse wheel values differ between computers?
Browsers and input devices report different delta units and step sizes. The test displays the reported unit alongside the values.
What does a Held button bitmask of 3 mean?
It means the left button (value 1) and the right button (value 2) are pressed at the same time. Middle adds 4, back adds 8 and forward adds 16.
Can I test a touchpad with this page?
You can, but touchpads may emulate buttons and scrolling in different ways, so results describe the touchpad settings as much as the hardware.
Does the reset button clear the pointer position?
Reset clears the button counters, the scroll totals, double clicks and the held mask. The position updates again as soon as you move the pointer.
Device checks and recordings run locally without AI or media uploads. Permission is requested only when starting capture. Download anything you want to keep before leaving the page.