Test every key on your keyboard to detect stuck or unresponsive keys.
Keyboard Tester
Test every key on your keyboard to detect stuck or unresponsive keys.
About the keyboard tester
How key detection works
The tester listens to keyboard events in your browser and marks each physical key as pressed, released, or already tested. It is useful for spotting keys that never send an event, keys that remain stuck, and layout differences between Windows and Mac.
Ghosting and simultaneous key presses
Some keyboards cannot report every combination of simultaneous keys. The live rollover counter helps you see how many keys the browser receives at once, which is useful when checking gaming keyboards, shortcuts, or suspected ghosting problems.
Local testing for mechanical, membrane, and laptop keyboards
All checks run locally in the browser, so typed keys are not uploaded. Browser and operating-system limits still apply: hardware-only keys such as Fn, brightness, or some media controls may be intercepted before the page can detect them.
FAQ
Common questions and answers about this topic.
A key doesn't respond — is my keyboard broken?
Not necessarily. First switch to your platform (Windows / Mac) and test the key here — if no state changes at all, the keyboard may indeed be faulty; if the key only fails in certain software, it may be software interception rather than hardware. Enable Track tested keys and test every key systematically to map all failing positions.
What is test tracking and how do I use capture?
Track tested keys keeps every pressed key marked as tested and shows live progress without changing normal page navigation. When you need to test browser shortcut keys such as F5, F11, or Tab, select Start capture; all supported keys then stay in the tester. Press Esc to record that key and end capture safely. After testing, select Generate report to export a copyable plain-text summary.
Why doesn't F5 refresh during capture?
Only an active capture session intercepts browser behavior for supported keys such as F5, F11, Tab, and Backspace, so those keys can be tested without reloading the page or moving focus. Select the capture button again or press Esc to end capture and restore normal browser behavior.
Why can't some keys be detected?
Some system keys (volume up/down, screen brightness, media controls, Fn key combos) are intercepted by the operating system or hardware directly, so the browser never receives the event and this tool cannot detect them. For these keys, use your operating system's built-in keyboard diagnostic instead.
Will my keystroke data be uploaded?
No. All key detection happens entirely in the browser — nothing is uploaded to a server and no data is written to any database. The "Generate report" copy function uses the browser's local clipboard API; the content never leaves your device.
Can I test mechanical, membrane, and laptop keyboards?
Yes. This tool detects the key events the browser receives, regardless of keyboard type (mechanical switches, membrane, scissor-switch), so both external desktop keyboards and built-in laptop keyboards work. For a full switch-by-switch check, enable Track tested keys and Full keyboard, then start capture when testing browser shortcut keys. Each pressed key is marked as tested, and the progress bar helps ensure you have verified every one.
How do I test for ghost keys or n-key rollover (simultaneous presses)?
Hold down several keys at once and watch the "Simultaneous keys: X (max Y)" line at the bottom. Membrane keyboards often recognize only a limited number of simultaneous keys (commonly 6 or fewer); beyond that, some presses get dropped — the ghost-key or key-blocking effect. Keyboards with N-key rollover can register many more at once. This number tells you your keyboard's simultaneous-press limit at a glance.
Why does the code shown differ from the key printed on my keycap?
The tool shows the physical key position reported by the browser (code / keyCode), independent of your current input method or keyboard language. For example, when you switch to a Chinese (Zhuyin) input method, the physical positions still map to the English-layout codes, so it shows that position's standard code rather than the character typed on screen — which means the hardware itself is working correctly.