How do I know a key is actually broken?

Press it a few times and watch both the on-screen keycap and the key-code readout. If neither reacts, no signal is reaching the browser at all. A key that registers only when pressed hard, or that needs several attempts, usually has debris or a worn contact under the cap rather than a failed switch.

Are my keystrokes recorded or sent anywhere?

No. Key events are handled entirely inside your browser tab and nothing is stored or transmitted. Closing the tab clears the whole test. That said, avoid typing passwords into any test page as a general habit.

What is the difference between code, key, and keyCode?

'Code' is the physical key's position on the board and never changes — the key left of S is always KeyA, even on a French AZERTY board. 'Key' is the character that position produces under your current layout. 'keyCode' is the old numeric value kept for backwards compatibility; it is deprecated but still handy when debugging older software.

Why does the browser tab not react to some keys?

A handful of keys never reach the page. The OS intercepts them first — Windows key combinations, Fn media keys on laptops, and on some machines PrtSc. Those staying unlit is normal, not a hardware fault.

Can I test a stuck key with this?

Yes. A stuck key shows up as a keycap that stays dark without you touching anything, because the keyboard keeps sending keydown events. Chattering keys are the other common fault: a single press registers twice, which you will notice as duplicate characters when typing normally.

My laptop keyboard has no numpad — does that matter?

No. The layout shown is a full-size 104-key board, so a laptop or tenkeyless keyboard will leave the numpad and some navigation keys untested. Ignore the ones your keyboard does not physically have and check that everything else lights up.

Keyboard Tester — Find Dead and Stuck Keys Online

Click this page first, then press any key. Nothing is recorded or sent anywhere.

code

—

key

—

keyCode

—

Location

—

Tested 0 of 0 keys 0%

Not yet tested

Press any key and it lights up on the on-screen keyboard below. Keys turn dark while held and stay green once tested, so a dead key is the one that never changes colour. The readout shows the exact code, key value, and legacy keyCode for each press, and the progress bar lists every key still untested. Nothing is recorded or sent anywhere — it all runs in your browser.

How it works

1
Click the keyboard area Click anywhere on the page first so the browser sends key events to it, then start pressing keys.
2
Work across the whole layout Press each key in turn. A key turns dark while you hold it and green once released. Watch the counter to see how many of the 104 keys have registered.
3
Check what is left over The 'Not yet tested' list shows every key that has never fired an event. If a key stays on that list after you press it, that key is dead.

Your data stays private

All processing happens entirely in your browser. No files, text, or data are ever sent to our servers. You can disconnect from the internet and this tool will still work.

Frequently asked questions

How do I know a key is actually broken?: Press it a few times and watch both the on-screen keycap and the key-code readout. If neither reacts, no signal is reaching the browser at all. A key that registers only when pressed hard, or that needs several attempts, usually has debris or a worn contact under the cap rather than a failed switch.
Are my keystrokes recorded or sent anywhere?: No. Key events are handled entirely inside your browser tab and nothing is stored or transmitted. Closing the tab clears the whole test. That said, avoid typing passwords into any test page as a general habit.
What is the difference between code, key, and keyCode?: 'Code' is the physical key's position on the board and never changes — the key left of S is always KeyA, even on a French AZERTY board. 'Key' is the character that position produces under your current layout. 'keyCode' is the old numeric value kept for backwards compatibility; it is deprecated but still handy when debugging older software.
Why does the browser tab not react to some keys?: A handful of keys never reach the page. The OS intercepts them first — Windows key combinations, Fn media keys on laptops, and on some machines PrtSc. Those staying unlit is normal, not a hardware fault.
Can I test a stuck key with this?: Yes. A stuck key shows up as a keycap that stays dark without you touching anything, because the keyboard keeps sending keydown events. Chattering keys are the other common fault: a single press registers twice, which you will notice as duplicate characters when typing normally.
My laptop keyboard has no numpad — does that matter?: No. The layout shown is a full-size 104-key board, so a laptop or tenkeyless keyboard will leave the numpad and some navigation keys untested. Ignore the ones your keyboard does not physically have and check that everything else lights up.

From the blog

How to Test a Keyboard Online and Fix a Dead Key Find dead, stuck, and chattering keys with a browser keyboard test, then work out whether it is dirt, a driver, or a failed switch. Read the post →

Keyboard Tester — Find Dead and Stuck Keys Online

How it works

Your data stays private

Frequently asked questions

From the blog

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