Mouse Test
Click each button, scroll the wheel and move the pointer to check a mouse or touchpad.
Keyboard Test
Press Start test, then press each key: a key that lights up on the diagram works, and one that never lights up has not registered. The diagram and readouts also show stuck keys, how many keys register at once and possible double typing.
Key—Code—Location—Modifiers—Repeat—
EscF1F2F3F4F5F6F7F8F9F10F11F12PrtScScrLkPause
`1234567890-=BackspaceInsHomePgUp
TabQWERTYUIOP[]\DelEndPgDn
CapsASDFGHJKL;'Enter
ShiftZXCVBNM,./Shift↑
CtrlOSAltAltOSMenuCtrl←↓→
Keys held now0Most at once0
Possible chatter (pressed again within 40 ms of release): none yet
Tested 0 of 87 keys · press Start test to begin
Press Start test and type to get a result you can copy or share.
While the test runs, keys are kept from triggering browser shortcuts where the browser allows it, so Tab and Enter cannot reach the buttons. Press Esc to stop; it is recorded as a key too. The test also stops when the page loses focus.
Keys not yet tested (87)
Escape, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, Print Screen, Scroll Lock, Pause, `, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, -, =, Backspace, Insert, Home, Page Up, Tab, Q, W, E, R, T, Y, U, I, O, P, [, ], \, Delete, End, Page Down, Caps Lock, A, S, D, F, G, H, J, K, L, ;, ', Enter, Left Shift, Z, X, C, V, B, N, M, ,, ., /, Right Shift, Up arrow, Left Ctrl, Left OS key, Left Alt, Space, Right Alt, Right OS key, Menu, Right Ctrl, Left arrow, Down arrow, Right arrow
Other keys seen (not on the diagram): none yet
Some keys can be handled by the operating system before the browser sees them: Fn, the Windows or Command key on its own, Print Screen on some systems, and media keys. Those may stay untested here even when they work. The diagram shows a US layout; on other layouts the key name may differ from what is printed on the cap. Keys held now and Most at once count only keys on the diagram.
Runs entirely in your browser. Test results, audio and video never leave your device.
How to test your keyboard
- Press Start test. Keys pressed before that are not recorded, and while the test runs, browser shortcuts are blocked where the browser allows it.
- Press each key once. It turns solid while held and stays tinted after you let go, and the readout shows its Key, Code, Location, Modifiers and Repeat.
- Open Keys not yet tested to see what is left. Number pad, media and other keys that are not on the diagram are listed under Other keys seen when the browser receives them.
- Hold several keys together, such as a game combination, and compare Keys held now and Most at once with the number of keys you are holding.
- Press any key you suspect of double typing several times at your normal speed, and check the Possible chatter line.
- Press Esc or Stop to finish; Esc is recorded as a key too. Reset starts over. If crumbs or dust may be causing a sticky key, lock the keys with the Keyboard Cleaner, wipe the keyboard, then test again.
Why is my keyboard double typing?
Double typing, also called key chatter, is one press of a key registering as two or more. It usually comes from a worn or dirty switch whose contacts bounce, or debris under the keycap. Press the suspect key several times: a new press within 40 ms of letting go is listed as possible chatter, with the gap in milliseconds.
How to check key rollover and ghosting
Rollover is how many keys a keyboard can register at the same time. Hold the combination you actually use, such as W, A, S and D with Shift and Space, and compare Keys held now with the number of keys you are holding. Limits depend on which keys are combined, so try more than one combination.
| Term | What it means | What you see here |
|---|---|---|
| N-key rollover (NKRO) | Every key registers, however many are held. | Every held key turns solid, and Keys held now matches your count. |
| 6-key rollover (6KRO) | Up to 6 ordinary keys plus modifiers, the limit of the basic USB keyboard report. | A seventh ordinary key usually does not turn solid, and Keys held now does not rise. |
| Blocking | The keyboard ignores a key in some combinations to prevent ghosting. | A held key does not turn solid while certain others are down. |
| Ghosting | A key you did not press registers because of the keys that are held. | A key you are not touching turns solid. |
How to test a laptop keyboard
- Fn is not on the diagram. The keyboard or the system handles it and changes what other keys send, so a web page normally never sees it. To check it, press a brightness key with and without Fn: one way should light a key on the diagram, the other should change the screen brightness.
- Many laptops lack some keys, such as Insert, Scroll Lock, Pause, Menu or the right OS key, or reach them through Fn, so those can stay under Keys not yet tested.
- Check the touchpad with the Mouse Test and a touch screen with the Touch Screen Test.
- When you are buying a used laptop, the used laptop checklist also covers the screen, speakers, webcam and ports.
What this test can detect
- Dead keys: a key never lights up on the diagram when you press it.
- Stuck keys: a key stays solid after you let go.
- Possible chatter: a key is listed because it registered again within 40 ms of being released.
- Rollover limits and ghosting: fewer keys turn solid than you are holding, or a key you did not press turns solid.
- Auto-repeat: Repeat reads Yes while a held key repeats, which is normal and not chatter.
- Layout and modifier mix-ups: Key shows the character your layout assigns, and Location tells left from right Shift, Ctrl, Alt and OS keys.
How it works
While the test runs, the page reads key-down and key-up events and blocks their default action where the browser allows it. Keys are matched by physical position (KeyboardEvent.code), not by the character they type, so each lights in the same place whatever your layout. The diagram is an 87-key US ANSI layout without a number pad.
A press is a key-down that is not an auto-repeat, or a lone key-up such as Print Screen can send on Windows. Keys held now counts the diagram keys that are down, Most at once keeps the highest count, and a key pressed again within 40 ms of its release is listed as possible chatter.
Limitations
- Keys the keyboard or system handles first, such as Fn, media keys and Print Screen on some computers, may never reach the page. They can stay untested even when they work.
- The test stops when the page loses focus, for example when the Windows key opens the Start menu or you switch windows or tabs. Press Start test to carry on; keys already tested stay marked.
- Browsers keep some shortcuts for themselves, such as Ctrl+W to close the tab and Ctrl+T to open a new one (Command+W and Command+T on a Mac), so avoid them while the test runs.
- Extra keys on ISO and JIS keyboards, such as the key beside the left Shift on ISO boards, are not on the US diagram. They are listed under Other keys seen.
- Polling rate, latency, actuation point and debounce time are not measured.
Frequently asked questions
How do I fix keyboard chatter?
Start by cleaning the key: blow compressed air under the keycap, or pull the cap off a mechanical keyboard and clear any debris. Some keyboards have a debounce setting in their software or firmware that ignores very quick second presses. A switch that keeps chattering needs replacing, which is simple on hot-swap boards; otherwise use the warranty or a repair service.
Can a website measure keyboard polling rate or latency?
No. A web page receives an event only when a key goes down or comes up, not the reports the keyboard sends, so the polling rate never reaches it; the time between key events reflects your fingers, the system's repeat rate and the browser. Latency, from key press to screen, needs external equipment such as a high-speed camera.
Why does my keyboard type the wrong characters?
Usually because of a layout setting, not a fault: US and UK layouts, for example, swap the @ and " keys. Key shows the character your layout gives each key; if it differs from the printed one, choose the matching layout in the keyboard or language settings. A stuck Shift, Ctrl or Alt key, shown solid after you let go, changes characters too.
How do I test the number pad?
Press Start test, then each number pad key. The diagram has no number pad, so each key is listed by name under Other keys seen, such as Numpad 1, and Location reads Numpad. With Num Lock off, Key can show End or ArrowDown instead of a digit, which is normal.
Does the keyboard test work on a Mac?
Yes: Command lights the OS key, Option lights Alt and Control lights Ctrl. macOS sends no key-up for keys released while Command is held, so the test releases them when Command comes up instead of showing them as stuck. Apple keyboards have no Print Screen, Scroll Lock, Pause, Insert or Menu key, and MacBooks no right Control, so those stay untested.