Press any key and watch it light up on screen. Keys you have tested stay highlighted, so you can work across the whole board and see at a glance which ones never registered.
What this keyboard test checks
This is a key registration test. The page listens for every key event your browser reports and marks the matching key on the layout, so a key that produces nothing on screen is a key your computer never received. That covers the most common hardware faults: a dead switch, a key wedged by debris, or a connection problem affecting part of the board.
It also makes intermittent faults visible in a way that ordinary typing does not. A key that works four times out of five is genuinely hard to notice while you are concentrating on words, but it becomes obvious when you are pressing keys deliberately and watching for the response.
What it cannot check is anything the browser never sees. Media keys, some function keys and vendor-specific shortcuts are often handled by the operating system or the keyboard firmware before a web page hears about them, so a key that stays dark is not automatically broken. The letters, digits, punctuation and modifiers that make up ordinary typing are all reported reliably.
Diagnosing a suspect key
Start by pressing every key on the board once and looking for anything that stays unlit. Then go back to the suspects and press each one twenty or thirty times, watching for misses. A key that registers every time is fine; a key that misses occasionally usually has debris under it or a switch beginning to fail.
The other common fault is the opposite problem: a key that repeats when you press it once, sending two or three characters. That is switch bounce, and it is a hardware fault rather than a setting. If several neighbouring keys fail together, suspect the connection or the controller rather than the individual switches.
- A key that never lights: dead switch, debris, or a key the browser cannot see
- A key that misses intermittently: debris under the cap, or a failing switch
- A key that fires twice from one press: switch bounce, a hardware fault
- Several neighbouring keys failing together: a connection or controller problem
- Everything dead on one half of the board: check the cable or the battery
Key rollover and ghosting
Rollover describes how many keys a keyboard can register at once. Ordinary typing overlaps far more than people realise, because you begin pressing the next key before releasing the last, and a keyboard with poor rollover will drop characters during fast typing while testing perfectly one key at a time.
Inexpensive membrane keyboards commonly manage two or three simultaneous keys, and some combinations block each other entirely because of how the key matrix is wired. That is ghosting, and it explains a specific and frustrating symptom: dropped characters that only appear when you type quickly, on a keyboard where every key passes an individual test. If that matches what you are seeing, the keyboard is not faulty so much as limited.
Layouts and why a key can be right but wrong
A key that produces the wrong character is usually a software mismatch rather than a hardware fault. The operating system decides what each physical key means, and if that setting does not match the keyboard in front of you, the letters will simply be in the wrong places. The classic symptoms are Y and Z swapped, which means a QWERTZ layout is selected, or the entire left side shifted, which suggests AZERTY.
Quotes and the at sign landing in unexpected places usually means a US layout is selected on a UK keyboard or the reverse. None of these are faults you can fix by cleaning the keyboard; they are corrected in the system keyboard settings, and this test will show you exactly which characters are affected.
When the keyboard is fine and typing still feels wrong
If every key registers cleanly and typing still feels laboured, the problem is more likely technique or ergonomics than hardware. Wrists resting at a sharp angle, a desk that is too high, or a keyboard positioned so your hands drift off the home row will all cost accuracy in ways that feel like the keyboard fighting you.
Once the hardware is confirmed good, the typing test is the more useful measurement. It will tell you whether your errors cluster around particular keys, which is a technique problem, or spread evenly, which usually means you are simply going faster than your accuracy supports.