Keyboard Tester
Click the keyboard below and press every key. Anything that does not light up is not reaching your computer.
Getting ready…
How It Works
The map shows a full-size 104-key keyboard. Each key lights while held and stays marked once your computer has registered it. Keys are matched by physical position, so any layout works. Keys outside the map, such as an extra ISO key or media keys, are listed underneath.
The test also times every release and the next press of the same key. Nobody can re-press a key in under 40 ms, so a faster press is the switch chattering: one keystroke typed twice.
While the keyboard has focus, keys like Tab, Space, the arrows and F5 are captured so they do not scroll or reload the page. To stop, press Esc twice quickly or click anywhere outside it. Nothing you type leaves your device.
Interpreting Your Result
A key you pressed that never lit up is dead: the keyboard is not sending it. Try it a few more times. If it stays dark, the switch or the keyboard’s circuit has failed at that spot.
A key marked red is chattering. One double press can be a fluke; two or more in one test means that switch is wearing out. On mechanical keyboards it can often be cleaned or replaced.
"Most at once" is rollover: how many keys your keyboard sends together. If you held more keys than it shows, the extra ones are ghosting. Most office keyboards manage only 2 to 6 in some combinations; gaming keyboards often handle all of them.
Some keys never reach any web page: Fn, and system shortcuts such as Ctrl+W or the Windows key on some computers. Those staying dark is expected.
Clicks misbehaving too? The mouse double click test catches a worn mouse switch the same way. Checking a new laptop? Run the dead pixel test on its screen and the mic test on its microphone as well.
Frequently Asked Questions
How do I know if a key on my keyboard is broken?
Press it on this page. If it does not light up on the map after several firm presses, the keyboard is not sending it, so the key or its circuit has failed. If it lights up but still does not work in an app, the problem is software or a setting.
Why does my keyboard type the same letter twice?
That is key chatter: a worn or dirty switch bounces and registers one press as two. This tester marks those keys red. Cleaning under the keycap can help; otherwise the switch needs replacing.
What is keyboard ghosting?
Ghosting is when a keyboard cannot send some combinations of keys held at once, so presses go missing. Hold several keys together here: if "Most at once" is lower than the number you are holding, your keyboard is ghosting.
Does this keyboard tester work on a laptop?
Yes. Most laptops have no numpad and fewer navigation keys, so those parts of the map stay dark. That is normal. Every key your laptop has should light up.
How do I fix a key that is not working?
If the key lights up here but not in an app, the keyboard is fine: check the keyboard language and layout in your system settings, and turn off Filter Keys on Windows, which ignores quick presses. If it stays dark here, pop off the keycap if you can, clean underneath with compressed air, and test again. A key that stays dead needs a new switch or keyboard.
Is what I type recorded?
No. Key presses are only counted in this page to draw the map, and nothing is stored or sent anywhere.