Keyboard Tester
Press any key on your physical keyboard to verify switch response, test multi-key rollover, and detect dead combining keys. Instant, private, and runs entirely in your browser.
Key Chatter Detection
Repeatedly tap a key to test switch bounce. If a single stroke produces multiple registrations or fails intermittently, the physical switch contact is chattering.
N-Key Rollover (NKRO)
Press 4 or 6 keys together. Quality mechanical keyboards register all simultaneous keys, while budget membrane boards block after 2 or 3 strokes.
Dead Keys & Accents
On international keyboards, keys like accent marks wait for a companion letter. Our tester detects these dead key signals without getting locked up.
Frequently Asked Questions About Keyboard Testing
The tester listens to browser keyboard events (keydown and keyup) and checks the exact physical code sent by your keyboard controller. When a key is detected, its virtual keycap lights up, confirming that the mechanical switch, membrane trace, and USB controller are functioning properly.
A dead key is a special modifier key on international keyboard layouts (such as accents like `´`, `^`, or `~`) that does not output a character immediately. Instead, it waits for the next keystroke to compose a combined accented character (like á or ê). Our tester detects dead key events and confirms your keyboard correctly sends the composition signal.
Ghosting occurs when certain combinations of keys fail to register or cause unpressed keys to trigger simultaneously due to shared matrix wiring. You can test your keyboard's key rollover by pressing 3 or more keys at the same time (e.g. W, A, S, D, and Shift) and verifying they all illuminate together in the live inspector.
The Fn key is typically handled entirely at the hardware or BIOS firmware level on laptops and never sends a scan code to the operating system or browser. Keys like Print Screen or Sleep may also be intercepted directly by your operating system window manager before the browser receives the event.
If a key fails to light up, test it multiple times to check for intermittent chattering. For mechanical keyboards, remove the keycap and clean dust or debris with compressed air, or test the hot-swap switch. For membrane laptops, ensure the scissor clip beneath the key is clean and free of sticky residue.