Keyboard Tester
Press every key and watch it light up, with a ghosting and rollover check.
While testing, every key (including Tab) is captured by this box. Press Esc or click outside to release the keyboard.
Ghosting check: hold the keys you use together (for example W + A + Shift + Space). If "Keys held now" is lower than the number of keys you are pressing, your keyboard is dropping some.
How to use the Keyboard Tester
- Click the testing area so it has focus.
- Press keys one by one. Each key lights up while held and stays tinted once it has worked.
- To test ghosting, hold several keys at once and watch the "held now" and "most at once" counters.
- Press Esc to release the keyboard, or Reset to start again.
About this tool
A key that fails only now and then is hard to pin down while typing. This tester shows a full-size keyboard, including the function row, navigation cluster and numeric keypad, and lights each key the moment your computer receives it. Keys you have already tested stay tinted, so a dead or unregistered key stands out as the one still blank. The panel also shows the technical details for the last key: the character it produced, its physical code, the legacy keyCode and whether it was the left, right or numpad version.
The rollover counter helps with ghosting. Cheaper keyboards can only report a few keys at once, especially in certain combinations, so in games one key press may be lost. Hold down the keys you care about, for example W, A, Shift and Space, and see whether the "held now" number matches what your fingers are doing. Keyboards with N-key rollover register every key simultaneously.
Keys are identified by their physical position, so the layout matches a US keyboard even if you type in another language. Some shortcuts, such as Windows key combinations or Cmd+Tab, are taken by the operating system before the browser sees them.
Frequently asked questions
A key does not light up. Is it broken?
Not necessarily. Check that the testing area has focus, then try the key in another app. Media keys, Fn and some vendor keys never reach the browser, and the operating system keeps shortcuts like Alt+Tab. If an ordinary letter key stays blank, the switch or connection is likely faulty.
What is ghosting and N-key rollover?
Ghosting is when pressing several keys together makes the keyboard drop or invent key presses. N-key rollover means every key is reported no matter how many are held. Many office keyboards manage 2 or 3 keys reliably; gaming boards often handle 6 or more.
Why does holding Cmd on a Mac confuse the counter?
macOS does not send key-release events for other keys while Command is held, so the tester clears the held list when Command is released to avoid stuck readings.
Are my keystrokes recorded?
No. Key presses are only used to light up the on-screen keys in this page. Nothing is stored or sent anywhere, and closing the tab discards everything.