Keyboard Test — check every key is detected
Press any key on your keyboard. Keys light up below the moment your browser detects them, so you can quickly spot one that's stuck, unresponsive, or double-firing.
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All tools run instantly in your browser — no installs, no accounts.
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Common keyboard problems this test can help catch
| Symptom | Likely cause |
|---|---|
| A key doesn't light up no matter how hard you press | Worn switch, debris under the keycap, or a damaged membrane contact beneath it. |
| A key registers twice from one press | Switch bounce — the contact briefly breaks and remakes during a single press, which the browser reads as two key-downs. |
| A key gets "stuck" and repeats on its own | Either a physically stuck key or a stuck modifier combination held by another app — try pressing the key again firmly to release it. |
| Multiple keys stop working only when pressed together | Usually a ghosting/rollover limitation — most keyboards can only reliably detect a certain number of simultaneous key presses. |
Frequently asked questions
Why don't some keys (like browser shortcuts) register?
Certain combinations, such as Ctrl+W or Ctrl+T, are intercepted by the browser itself for tab and window management before the page ever sees them. This is a browser-level restriction, not a fault with your keyboard.
What does "repeats detected" mean?
It counts key-down events that fire from holding a key rather than a genuine second press. A small number is normal — browsers repeat a held key automatically after a short delay. Repeats appearing without you holding anything down is what's worth investigating.
Does this test work with an on-screen or virtual keyboard?
Yes, as long as the virtual keyboard sends standard key events to the browser, but the layout on this page is built around a physical keyboard's key positions, so the visual grid may not match a virtual layout exactly.
My laptop's function keys behave differently than expected.
Many laptops require an Fn key combination to send a standard function-key signal versus a hardware shortcut (brightness, volume, etc.). Check your system's keyboard settings if F-keys aren't registering as expected.