Keyboard Tester – Check Every Key Works
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Keys tested
0
Held now
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Most at once
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Last key
Green = worked at least once · highlighted = held down now.
Recent key presses
Press any key to start. No key presses are sent or saved.
About Keyboard Tester
Press each key on your keyboard. It lights up while held and stays marked once tested, so any key that never lights up is the one that isn't working. The panel shows the key's name and code, and how many keys you're holding at once.
Dead keys, keys that register twice from one press, and keys that stick down are the usual faults on worn or spilled-on keyboards. Working through the layout here makes each one obvious: a dead key never turns green, a chattering key shows repeated presses in the history, and a stuck key stays lit after you let go.
The rollover counter shows how many keys the keyboard reports at the same time. Many cheaper keyboards drop some combinations when three or four keys are held — which matters in games. Hold several keys together and watch whether each one lights up.
Some keys can't be tested in a browser: the operating system keeps keys like the Windows/Command key combinations, Print Screen and Fn to itself, and some laptops handle media keys before the browser sees them. Everything else on a standard layout is covered.
What you can use it for
- Check a second-hand or refurbished keyboard before you buy it.
- Find which key stopped working after a spill.
- Detect a chattering key that types a letter twice.
- Test how many keys a gaming keyboard registers at once.
- Look up a key's code for programming or remapping.
How it works, step by step
- 1
Click the tester
Make sure the page has focus so it receives your key presses.
- 2
Press every key
Each key lights up while held and stays marked once it has worked.
- 3
Look for gaps
Keys that never light up aren't registering.
- 4
Test combinations
Hold several keys together and check the rollover count.
Frequently asked questions
A key doesn't light up. Is it broken?
If other keys work and that one never lights up, it probably isn't sending a signal. Try it in another program to be sure — a few keys (Fn, Print Screen, some media keys) are handled by the operating system and never reach a web page.
What is key rollover?
The number of keys a keyboard can report pressed at the same moment. '6-key rollover' means six at once; 'N-key rollover' means any number. Hold keys together here to see where yours stops.
Does this work with any keyboard layout?
It uses each key's physical position, so it works for any layout. The on-screen labels show a US layout; a key on a French or German keyboard lights up in the same position.
Is what I type recorded?
No. Key presses are shown on this page only and are never sent or stored.