Let's check your keyboard.
Press every key — each one lights up so you can spot a stuck or dead key. Your test data stays on your device.
Each key turns green once it works. Find one that won't light up? That's your stuck or dead key.
CheckMyMic's keyboard test is a free online key checker that runs entirely in your browser: press any key and it lights up on the on-screen keyboard, so stuck, dead or mis-mapped keys show up in seconds. No download, no signup, and your test data stays on your device.
How the keyboard test works
Every time you press a key, your browser fires a keyboard event carrying that key's physical code — no permission prompt needed. We match the code against the on-screen layout: the key flashes while held and stays green once it has proven itself. Any key that refuses to turn green no matter how hard you press is your stuck or dead key.
The tester deliberately swallows the browser's default behaviour for Space, Backspace and the arrow keys so the page doesn't scroll mid-test — but Tab keeps working normally, so keyboard-only users are never trapped. Everything happens locally: your keystrokes are never stored or sent anywhere.
What the readings mean
- Keys tested — how many distinct keys have registered so far, out of the full on-screen layout.
- Key / Code — what your last press produced: the character, and the physical key code the browser saw.
- WPM — typing speed in the standard measure of five characters per word, timed from your first keystroke in the box.
- Accuracy — the percentage of typed characters that match the sample sentence.
- Rollover — the most keys this tester has seen you hold down at once this session, an NKRO-style readout. It's a floor, not a ceiling — OS and browser limits can under-report your keyboard's true hardware rollover.
- Chatter — keys that double-registered: two keydowns of the same key less than 35ms apart that weren't an OS auto-repeat. Flagged automatically and highlighted on the on-screen key.
- KPS — keys per second in the 5-second spam test. 5+ is solid, 8+ is fast, 12+ is blazing.
Keyboard test FAQ
Why doesn't this work with my phone's on-screen keyboard?
On-screen keyboards type through an autocorrect/input layer rather than sending real per-key events, so many of them report no usable key code to the browser. This tester is built for physical keyboards — on a phone, use the typing box to at least confirm text input works.
A key lights up but types the wrong character — is it broken?
The key is fine. The tester tracks the physical position of each key (the KeyboardEvent code), while the character it types depends on your keyboard layout. If you use a non-US layout, some labels won't match what you type — that's expected.
Are my keystrokes recorded or sent anywhere?
No. Key events are handled entirely in your browser just to light up the on-screen keys and count coverage. Nothing you press or type here is stored or sent to a server.
A key won't light up at all — what should I do?
First confirm it fails in other apps too. If it does, power the keyboard off and on (or re-pair over Bluetooth), pop the keycap and clean underneath, and check for driver or remapping software. Our Windows 11 and macOS keyboard guides walk through the fixes in order.
Why don't Fn or media keys register?
The Fn key is handled inside the keyboard's own firmware and never reaches the operating system, so no browser can see it. Media and brightness keys are often intercepted by the OS before the browser gets them — silence from those keys doesn't mean they're broken.
What is keyboard chatter and how do I test for it?
Chatter is a single key press that registers as two — a worn or dirty switch bounces on contact and the controller reads that bounce as a second keydown. This tester watches every key's timing and flags it automatically: two keydowns of the same key under 35 milliseconds apart (that aren't your OS auto-repeating a held key) light that key up with a warning and update the Chatter tile. Our keyboard typing double letters guide covers the cleaning and debounce fixes.
How many keys can my keyboard register at once?
That's your keyboard's rollover, sometimes marketed as N-key rollover (NKRO). The Rollover tile tracks the most keys this tester has seen held down simultaneously in your session. Hold down a chord and watch it climb — but treat the number as a floor, not a ceiling: OS-level key-combo handling and some browsers can under-report true hardware rollover, so this reading can read lower than your keyboard's actual NKRO spec.
What's a good keys-per-second score?
The Key spam test grades your 5-second burst: under 5 keys/second is warming up, 5+ is solid, 8+ is fast, and 12+ is blazing. Most people land in the solid-to-fast range mashing with one hand; alternating hands or using more fingers pushes it higher. It's a fun speed check more than a diagnostic — a lower score doesn't mean anything is wrong with your keyboard.