Keyboard Tester — Test Every Key Online
Find dead, stuck or misbehaving keys. Press each key and watch it light up on the on-screen keyboard; tested keys stay marked, and the key code and value appear for every press.
Click on the page first if keys don't register. Some keys, such as Fn, the Windows key or Print Screen, may be captured by your operating system and never reach the browser.
How to test your keyboard
- Click on the page so it has keyboard focus.
- Press each key one at a time. Keys turn blue while held and green once tested.
- Keys that never light up may be dead; a key that stays blue after release may be stuck.
Diagnosing keyboard problems
If a key does not register, try it in another app to rule out the browser. A key that works intermittently often has dirt or debris under it; compressed air or, on mechanical keyboards, removing the keycap usually helps. Liquid spills can disable rows of keys at once.
event.code identifies the physical key position (for example KeyA) regardless of layout, while event.key shows the character it produces with your current layout. That is useful for checking international layouts and remapping software.
To test key rollover (how many keys can be pressed at once), hold several keys together and watch how many light up. Many laptop and budget keyboards register only some combinations; gaming keyboards often support full rollover.
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Frequently asked questions
Why are some keys not detected?
Fn, media keys and some system shortcuts are handled by the keyboard or operating system and never reach the browser.
How do I fix a stuck key?
Unplug or power off, then clean around the key with compressed air. On mechanical keyboards, gently remove the keycap to clean underneath.
Does this test work with any layout?
Yes. The on-screen board shows a U.S. layout, but every key press is reported, including keys from other layouts.
What is key rollover?
The number of keys a keyboard can register simultaneously. Hold several keys at once to test it.