What this keyboard test checks
- Dead keys: any key that never lights up is not reaching the operating system.
- Stuck keys: a key shown as held after you release it is physically or electrically stuck.
- Chatter (double input): the press counter jumping by more than one per press reveals a bouncing switch.
- Rollover and ghosting: hold groups of keys — WASD plus Space plus Shift is the classic gaming check — and confirm the held count matches your fingers.
- Layout mapping: the history shows both the physical key code and the character your layout produced.
How to run a full check
- Start the test, then type across every row from Escape to the arrow keys.
- Press each modifier (Shift, Ctrl, Alt/Option, Meta/Cmd) on both sides individually.
- Hold 4–6 keys you use together in games and confirm they all stay lit.
- Press suspect keys ten times slowly and confirm the counter rises by exactly ten.
- Reset and repeat after cleaning or re-pairing if any key misbehaved.
Fixing common keyboard problems
A single dead key
Pull the keycap (on mechanical boards) and clear debris; compressed air helps on laptops. If it stays dead across apps and a reboot, the switch or membrane contact has failed.
Random missed keystrokes on wireless
Move the receiver closer or to a front USB port, replace batteries, and avoid USB 3.0 hub interference. Re-test wired if the board supports it to isolate the radio link.
Whole keyboard unresponsive
Try another USB port, then another computer. On laptops, an unresponsive built-in keyboard with a working external one points to the internal ribbon or controller.
Wrong characters appear
Check the OS input language and layout first — a UK/US or QWERTY/AZERTY mismatch relabels many keys. The physical positions in this test still register correctly regardless of layout.
Testing the rest of your setup? Check your mouse buttons, your microphone, or measure your typing-adjacent click speed with the CPS test.
Keyboard test questions
Start the test and press every key one by one. A key lights up while held and stays marked once it has registered. Any key that never lights up is not delivering input to the operating system — try it in another app to confirm, then clean under the keycap or test another keyboard.
Rollover is how many keys a keyboard can register at once — hold several keys together and watch the "held now" counter. Ghosting is when pressing certain key combinations produces an extra key you never pressed, common on basic membrane boards. NKRO (n-key rollover) keyboards register every key simultaneously.
The diagram places keys by physical position (the KeyboardEvent code), while the key history also shows the character your active layout produced. On AZERTY, Dvorak, or other layouts the printed character differs from the US position — that is a layout setting, not a hardware fault.
The tester intercepts most browser shortcuts while capturing, but the operating system handles some combinations (like Alt+Tab, Cmd+Tab, or Win+L) before the browser ever sees them. Those keys still register on their own — test modifier keys individually.
Repeated characters from a single press ("chatter") usually mean a worn or dirty switch, most common on aging mechanical keyboards. Watch the press counter while pressing once; if it jumps by two, clean the switch or use the vendor’s debounce utility. Holding a key normally repeats after a delay — that is the OS key-repeat, not chatter.
Yes. It tests whatever keyboard the operating system delivers input from — built-in laptop keyboards, USB, and Bluetooth boards. If a Bluetooth keyboard drops keystrokes, re-pair it and test again; intermittent wireless links look identical to failing switches.