Keyboard Tester
Press each key and watch it light up on a full virtual keyboard — a fast way to find dead, stuck, or chattering keys and check ghosting. Switch between Windows and Mac labels, and see each key's code as you go. Want to test your typing speed instead? Try the Typing Speed Test.
Press any key to light it up. Click the keyboard so Space, Tab, and arrows test here instead of scrolling the page.
Recent keys
Press keys to see them logged here.
How it works
Click the keyboard to focus it, then press your keys. Each press is matched to the physical key by its hardware code — so the left and right Shift, Ctrl, and Alt are told apart, and the numpad is separate from the number row. A key turns solid while held, then stays filled as testedonce you've hit it, so you can track your progress across all the keys. The panel shows each key's key, code, and keyCode, plus live Caps, Num, and Scroll Lock status.
Ghosting & key rollover
Hold several keys down at once to test rollover — how many keys your board reports simultaneously. Budget keyboards cap at 2 or 6 keys; gaming boards with N-key rolloverregister them all. If holding three nearby keys lights up a fourth you never pressed, that's ghosting, a limitation of the keyboard's matrix that can drop inputs during fast typing or gaming.
Dead, stuck & chattering keys
- Dead — never lights up; debris, a worn switch, or a connection fault.
- Stuck — stays lit after you let go.
- Chatter — one press logs two or more times in the recent-keys list.
- Cleaning with compressed air fixes many of these; persistent faults mean a worn switch.
Which keys can't be tested?
Some keys are grabbed by the operating system before the browser sees them, so they won't register on any web tester — typically the Windows key, Print Screen, and Fncombinations, plus OS-level shortcuts like Alt+Tab. That's normal and doesn't mean the key is broken. Ordinary keys that fail to light up are the ones worth worrying about.
Test more of your setup
Benchmark how fast you can mash keys with the Keyboard Clicker, measure real words-per-minute on the Typing Speed Test, or check your mouse with the Mouse Tester.
Frequently asked questions
How do I test my keyboard?
Click the on-screen keyboard to focus it, then press each physical key one at a time. Every working key lights up and is marked as tested, so you can sweep across the whole board — letters, numbers, modifiers, function row, arrows, and numpad — and instantly spot any key that never lights up. A dead key that won't highlight points to debris, a worn switch, a driver problem, or a loose connection.
Why don't some keys light up?
A few keys are intercepted by your operating system before the browser ever sees them, so they can't be tested on any web page. The most common are the Windows key, Print Screen, and Fn-based combinations, and on Mac some Command shortcuts. The tester also can't fire OS-level combos like Alt+Tab or Cmd+Tab. If an ordinary letter, number, or arrow key doesn't light up, though, that's a genuine sign the key isn't registering.
How do I test for ghosting and key rollover (NKRO)?
Key rollover is how many keys your keyboard can report at once. To check it, hold several keys down together and watch how many stay lit. Cheap keyboards often stop at 2 keys (2KRO) and most do 6 (6KRO), while gaming boards advertise N-key rollover (NKRO), registering every key no matter how many you press. Ghosting is the related fault where pressing three nearby keys makes a fourth key you didn't touch light up — a sign the keyboard's matrix can't keep them separate.
What is a stuck or chattering key?
A stuck key stays highlighted after you lift your finger, which usually means debris under the switch or mechanical wear. Chatter is the opposite-looking fault: a single press registers two or more times because the switch contacts bounce. Both are common in older or heavily used mechanical keyboards. Watching whether a key releases cleanly, and whether it appears once or several times in the recent-keys log, helps you tell them apart.
What's the difference between the Windows and Mac layouts?
The physical keys are the same; the labels and bottom row differ. Switching to Mac relabels the modifiers — Control, Option (Alt), and Command (the Windows key), plus Return and Delete — and hides Windows-only keys like Menu and Print Screen. Pick the layout that matches your keyboard so the labels read correctly; it doesn't change which physical keys are detected, since the tester identifies keys by their hardware position rather than the printed legend.
A key doesn't work — how do I fix it?
First rule out software: try a different browser and, if you can, another computer, to confirm it's the hardware. For a physical fix, power down, then clean around the key with compressed air and, on mechanical boards, gently remove the keycap to clear debris under the switch. Sticky keys often come back to life after cleaning; a switch that still won't register or that chatters after cleaning is likely worn and may need replacing or resoldering.