Keyboard Test
Press every key on your keyboard. Each key lights up on the screen, so you can instantly spot dead keys, double-typing and ghosting. Free, no download.
Start pressing keys
Click here first if keys don't react — the page needs focus.
Keys tested0
Keys held right now0
Max held together0
Possible chatter0
Last key: —
How to use the keyboard tester
- Press each key one by one. Keys turn blue while held and green once they've worked.
- Any key that stays grey after pressing is not registering.
- Keys that turn orange fired twice almost instantly — a sign of chatter on worn switches.
- To test ghosting, hold several keys together (try W, A, S, D + Shift + Space) and watch “Max held together”.
Fixing a key that doesn't work
- Clean it. Remove the keycap (mechanical keyboards) and blow out dust with compressed air. On laptops, tilt the laptop and blow along the edges of the key.
- Check another USB port or another computer to separate hardware problems from software problems.
- Update or reinstall the driver (Windows: Device Manager → Keyboards → Uninstall device, then restart).
- Check remapping software such as gaming keyboard utilities or AutoHotkey that may block a key.
- Chatter on a mechanical switch can often be fixed with a few hundred fast presses or contact cleaner; otherwise the switch needs replacing.
Frequently asked questions
How do I know if a key is broken?
Press it once. A working key lights up and turns green after you release it. If nothing happens, the key is not registering — try cleaning under the keycap or test the keyboard on another computer to rule out drivers.
What is key chatter (double-typing)?
Chatter is when one press registers as two or more presses — common on worn mechanical switches. This test counts presses and flags any key that fires twice within 40 ms of being pressed.
What is ghosting and N-key rollover?
When you hold many keys at once, cheaper keyboards stop registering some of them (ghosting). Hold several keys together — the “Keys held right now” counter shows how many your keyboard can register at the same time. Gaming keyboards usually support 6 keys or more (NKRO).
Why don't the Fn, Print Screen or media keys light up?
Some keys are handled by the keyboard itself or by the operating system and never reach the browser — for example Fn, and on some systems Print Screen or volume keys. That doesn't mean they are broken.
Does it work with non-US layouts?
Yes. The test uses physical key positions, so it works with any layout (UK, German, French and so on). Keys that exist only on certain layouts are highlighted in the event log.