Keyboard Test
Press each key and watch it light up to find dead, stuck and double-typing keys.
Mouse Test
Move, click and scroll in the test area: each button lights up on the mouse diagram and is counted, scrolling is counted by direction, and the trail shows how smoothly the pointer moves. It works with touchpads too.
- Position
- —CSS pixels from the top-left corner of the test area
- Left clicks
- 0
- Right clicks
- 0
- Middle clicks
- 0
- Back / Forward clicks
- 0 / 0
- Double-clicks
- 0
- Scroll
- Up 0 · Down 0 · Left 0 · Right 0Wheel events as the browser reports them; a trackpad sends many per swipe
- Scroll flips
- 0Changes of direction within 150 ms; if this rises while you scroll one way, the wheel may be worn or dirty
- Last event
- —
Move, click or scroll inside the test area
| Button | Suspected double-clicks | Last gap |
|---|---|---|
| Left | 0 | — |
| Right | 0 | — |
| Middle | 0 | — |
| Back | 0 | — |
| Forward | 0 | — |
Click each button normally for a minute. Presses of one button less than 60 ms apart are flagged here.
Presses of one button less than 60 ms apart that keep being counted usually point to a worn or dirty switch; a single count can come from a very fast deliberate click. Last gap is the time between the latest two presses of each button.
The right-click menu is disabled inside the test area. Side buttons only register in browsers that report them.
Runs entirely in your browser. Test results, audio and video never leave your device.
How to test your mouse
- Move the pointer slowly around the black test area. The trail should follow smoothly, without sudden jumps or a shaky line.
- Click the left and right buttons and press the wheel. Each lights up on the diagram while held and adds one to Left clicks, Right clicks or Middle clicks.
- Press the side buttons. They add to Back / Forward clicks, and inside the area they are kept from moving the page back or forward where the browser allows it.
- Double-click with the left button and check that Double-clicks rises by one. Then click each button normally for a while: in the Double-click fault check, Suspected double-clicks counts presses of one button less than 60 ms apart, and Last gap shows the time between its latest two presses. Once one button does it twice, the line under the table warns of a possible double-click fault.
- Scroll down for a while, then up, then sideways with a tilting wheel or a touchpad. Scroll counts each direction and Last event shows the step in px, lines or pages. Scroll flips should stay at 0 while you scroll one way.
- Press Reset to start over.
Why does my mouse double-click when I click once?
A mouse that double-clicks on its own usually has a worn or dirty switch: its contacts bounce, so one press reaches the computer as two presses milliseconds apart. Click one button normally for a minute. If presses less than 60 ms apart keep being counted for that button, the switch is the likely cause; a single count can come from two very fast deliberate clicks.
How to tell if a mouse is faulty
Use the test area the way you normally would for a minute, then compare what you see with these common faults.
| Problem | What you see here | Likely cause |
|---|---|---|
| Drags drop or a held click lets go | Its count rises again while you keep holding the button, and it may flicker on the diagram. | A worn or dirty switch. |
| The scroll wheel jumps | Scroll flips rises while you scroll one way, and Up rises while you scroll down, or Down while you scroll up. | A dirty or worn wheel encoder. |
| The pointer skips or shakes | Long straight jumps or a wobbly line in the trail while you move slowly. | A dirty sensor, a glossy or glass surface, or a weak wireless signal or battery. |
| A button does nothing | Its count stays at 0 and it never lights up on the diagram. | A failed switch, a remap in the mouse software, or, for side buttons, a browser that does not report them. |
How to test a laptop touchpad or trackpad
- Tap and click in the test area. Both count as Left clicks; if taps do nothing, tap to click may be off in the touchpad settings.
- Right-click with a two-finger tap or click, or the lower-right corner, depending on your settings. It should count under Right clicks.
- Swipe two fingers up, down and sideways. Each swipe sends many wheel events, so Scroll rises quickly. The direction follows your scrolling setting, so with natural scrolling a swipe up counts as Down.
- System gestures, such as switching apps with three or four fingers, are handled by the system and do not reach the page.
- A touch screen is a different part: check it with the Touch Screen Test. For a whole second-hand laptop, follow the used laptop checklist.
What this test can detect
- Whether each button registers: left, right, middle, back and forward, with a count for each.
- Suspected unintended double-clicks: presses of one button less than 60 ms apart, with the last gap in ms, and a possible-fault warning once a button does it twice. A count is a suspicion, not proof of a fault.
- Buttons that let go while held: the count rises again while you keep the button down.
- Scrolling in all four directions, including a tilting wheel and touchpad swipes.
- A scroll wheel that steps the wrong way, counted under Scroll flips.
- Pointer skips and jitter in the movement trail.
How it works
The page reads pointer events in the test area. A press counts when a button goes down, and pointer capture keeps a release outside the area registering. The fault check times the presses of each button separately and counts gaps under 60 ms.
Wheel events are sorted by their larger axis into up, down, left or right. An up or down event that reverses the one before less than 150 ms later is a scroll flip; the step straight back is not counted again. The trail keeps up to 300 positions, fades over 2 seconds and follows the positions the browser delivers, not every report the mouse sends.
Limitations
- DPI and polling rate are not measured here: the Mouse DPI Test and the Mouse Polling Rate Test estimate them from what the browser receives. Click latency is not measured.
- Inside the test area, the right-click menu, middle-click autoscroll and back and forward navigation are blocked where the browser allows it, so each button can be pressed without leaving the page. Outside it they work normally.
- Five buttons are counted: left, right, middle, back and forward. Side buttons register only in browsers that report them, and buttons beyond these five are ignored.
- Double-clicks counts the browser's own double-click events: primary button only, at your system's double-click speed. Deliberate double-clicks count too, so a high number there is not a fault.
- The trail shows skips and jitter you can see, not the sensor's full resolution.
Frequently asked questions
Does this mouse test measure DPI or polling rate?
No. The page sees pointer positions after your pointer speed settings are applied, at the pace the browser delivers them, so neither DPI nor polling rate can be read from them. The Mouse DPI Test estimates DPI from raw movement over a measured distance, and the Mouse Polling Rate Test estimates the reports per second the browser receives.
Can a double-clicking mouse be fixed?
Sometimes. Compressed air around the button can clear dirt from the switch, but a worn switch has to be replaced, which usually means soldering, so check the warranty first. Some mouse software has a debounce setting that ignores very quick second clicks; it hides the symptom rather than repairing the switch.
What do the side buttons on a mouse do?
They usually go back and forward in web browsers and many other apps. In the test area, each press is counted under Back / Forward clicks. If that stays at 0 / 0, your browser may not report them, or the mouse software may map them to keys, which the Keyboard Test can show.
How do I test the middle mouse button?
Press the scroll wheel down until it clicks. The wheel lights up on the diagram while you hold it and Middle clicks rises by one; autoscroll is blocked in the test area, so the page stays still. Many touchpads have no middle button unless a gesture is set for it in the touchpad settings.