Handy tools
Keyboard Test
Check that every key works — spot dead keys, stuck keys and ghosting, right in your browser.
Press the keys one by one to check that your keyboard responds. A key lights up while you hold it and stays tinted once it has registered — any key that never lights up is probably dead or failing.
Ghosting and rollover: hold several keys together and watch “Held now”. That number is how many keys reach the browser at the same moment. If a key you aren't pressing lights up, that's ghosting; if a held key stays dark, the keyboard is blocking that combination. Fn never reaches the browser, and keys the OS or browser grabs first (Win/⌘, Print Screen, shortcuts like Alt+Tab or Ctrl+W) may not show up.
The on-screen board is a US (ANSI) layout — main block, F-keys and arrows, 78 keys in all. Keys are matched by physical position (event.code), so on UK, AZERTY or QWERTZ keyboards the right spot lights up, just with the US legend. Keys not drawn here — the numpad, Insert/Delete/Home/End/Page Up/Page Down and the extra ISO key next to left Shift — still appear under Last key and event.code.
Keys tested
0/78
Held now
0
Last key
—
event.code
—
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A free keyboard tester that runs in your browser. Press each key and it lights up on an on-screen US (ANSI) board of 78 keys — the main block, F-keys and arrows. Keys that have registered stay tinted, so a key that never lights up is easy to spot. Hold several keys at once and the “Held now” counter shows how many reach the browser together, which is how you check rollover and catch ghosting. Keys are matched by physical position, so UK, AZERTY and QWERTZ boards work too. No download or install.
Frequently Asked Questions
Q. How do I find a dead key on my keyboard?
A. Press every key once. Each key that registers stays tinted on the on-screen board, so any key still blank afterwards is the one to check.
Q. Can I test anti-ghosting and N-key rollover?
A. Yes. Hold several keys together and read the “Held now” counter: it shows how many keys reach the browser at the same time. A key lighting up that you didn't press is ghosting.
Q. Does it work with UK, AZERTY or other layouts?
A. Yes. Keys are detected by physical position (event.code), so the right spot lights up on any layout, but the board is drawn as US ANSI with US legends. The numpad, navigation cluster and the extra ISO key aren't drawn; they still show under Last key.
Q. Why don't Fn, the Windows key or Print Screen register?
A. Fn is handled inside the keyboard and never sent to the computer, and the OS or browser often grabs Win/⌘, Print Screen and shortcuts like Alt+Tab before the page sees them. That doesn't mean the key is broken.