Keyboard Tester
Press any key and it lights up on the layout. Also catches chattering (one press typed twice) and counts how many keys register at once. Windows and Mac.
- Keys tested
- 0
- Max at once
- 0
- Possible chatter
- 0
- Last key
- –
Event log
What this keyboard test shows
Each key you press turns dark on the layout and stays outlined in red afterwards, so you can see which keys you have already checked. Go across the keyboard and any key that does not respond stands out. The test also counts chatter, when one press types twice, and the most keys that register at once, which reveals rollover limits and ghosting. It is handy for a new keyboard, a used one you are about to buy, or a key that sometimes doubles letters.
How to use it
Click the page once and start pressing keys. The event log lists the key code, the character typed and the time since the previous press. Suspected chatter is highlighted in red in the log and on the key itself. Reset clears everything. Mac keys are labelled command and option, and on Korean keyboards the Han/Eng and Hanja keys map to the right Alt and Ctrl positions.
How chatter is detected
When a switch contact wears out or collects dust, a single press can bounce and send several signals. The tool counts a press as chatter if the same key reports a new press within the threshold after it was released, 40ms by default. A deliberate double tap is almost never that fast. Lower the threshold to 25ms when testing very fast gaming taps, or raise it to 60 or 80ms to catch only clear cases.
Keys no website can see
The Fn key, most laptop brightness, volume and backlight keys, and shortcuts the operating system grabs first (Windows key combinations, Mission Control on a Mac) never reach the browser. Their silence here does not mean they are broken. Key presses are only displayed on this page and are never stored or sent.
FAQ
Some keys do not light up.
The Fn key, many laptop brightness and volume keys, and shortcuts the operating system intercepts never reach the browser, so no web page can see them. If other keys stay dark, the key or its switch may be faulty.
How is chatter detected?
If the same key sends a new press within a very short time after being released (40ms by default), it is counted as chatter. That gap is too short for a deliberate double tap, so it usually means a bouncing switch contact. Adjust the threshold if you are testing very fast taps.
What does max simultaneous keys mean?
It is the highest number of keys held down at once that the keyboard reported. If some keys drop out when you press several together, the keyboard has a rollover limit or ghosting. Try the combinations you use in games.
Is anything I type stored or sent?
No. Key presses are only displayed on this page and never sent or saved. You can test every key without typing anything sensitive.