Maybe a specific key combination won't register while gaming, or the same letter keeps getting typed twice while you're writing. Either way, it's worth confirming whether the keyboard itself is the problem. This is also handy before buying a used keyboard, letting you confirm every key still works without installing any software — everything happens visually, right in the browser.
What you can check with Dagochim's keyboard test
- A full on-screen keyboard layout: the main key block, arrow keys, and numeric keypad are all drawn out to mirror a real keyboard.
- Detection by physical key position: keys are identified by their actual physical location rather than the character they produce, so the test stays accurate even if you're using a remapped or non-standard layout.
- Tested / currently held / chattering color states: any key you've pressed at least once turns green, the key you're currently holding is highlighted, and any key where chattering is detected turns orange.
- Simultaneous key count (rollover): shows the highest number of keys you've held down at once, letting you check how many simultaneous inputs your keyboard actually supports for gaming.
- Input log: a table of the last 20 keys pressed, along with their key name, physical code, and timestamp.
How to test your keyboard
- Open the Keyboard Test tool.
- Click the on-screen keyboard diagram to give the test area focus.
- Press each key on your physical keyboard one at a time. A key turning green on screen confirms it registered correctly.
- Work through every key to make sure nothing is left un-highlighted. Any key that shows no reaction at all has a genuine problem.
- Also try pressing a combination you use often while gaming (like WASD plus Shift plus Space) all at once, to confirm the combination registers fully together.
Why this tests by key code instead of by character
Every keyboard event actually carries two separate pieces of information: "which character this produces" and "which physical key was pressed." This test works off the physical key code rather than the character, which means it correctly identifies "the key in the Q position" even if your input method is switched to another language, or if you've remapped to a different layout like Dvorak. Certain special keys — for instance the Hangul/Hanja toggle keys found on Korean keyboards — can arrive as different codes depending on the operating system and browser, so those specific keys get extra handling to make sure they're still recognized as the same physical key.
What chattering, ghosting, and rollover actually mean
Chattering happens when a key's internal switch contact bounces unstably for a moment, causing a single physical press to register as two or more rapid signals. It's most common on mechanical keyboards after the switches have worn down from extended use. This test treats any repeat signal from the same physical key within 40 milliseconds as chattering and flags it in orange. If a particular letter keeps appearing doubled while you type normally, that switch may be worth cleaning or replacing.
Rollover (sometimes called N-key rollover, or NKRO) describes how many keys held down at the same time will all still register correctly. Cheaper membrane keyboards often only support a limited number of simultaneous key combinations before additional presses get silently dropped — a limitation commonly called "ghosting." Most gaming-oriented keyboards instead support full N-key rollover, meaning every key registers no matter how many others are already held. The "max simultaneous keys" number shown by this test gives you a practical sense of where your own keyboard's limit actually sits.
What's different on Mac vs. Windows
This tool automatically detects whether you're on a Mac or Windows machine and adjusts the labels accordingly — showing ⌘ (Command) in place of the Windows key, and ⌥ (Option) in place of Alt, on Mac. On Korean physical keyboards, the Hangul/Hanja toggle keys that sit where the right Alt and Ctrl keys usually are also get labeled appropriately.
Common problems and how to fix them
- Clicking the keyboard diagram doesn't do anything: the test area hasn't received focus yet. Click directly on the prompt text shown on screen to focus it, then try pressing keys again.
- None of a specific key combination works on my laptop: budget keyboards often have a hard limit on simultaneous key detection. Press the problematic combination one key at a time, adding keys progressively, to find exactly which addition breaks the combination.
- The Hangul/Hanja keys show up in an unexpected spot: depending on the operating system and browser, these keys can arrive under a different code than expected, which can cause them to initially appear in the "extra recognized keys" list instead of their usual position — but they're still being tracked and tested correctly either way.
Frequently asked questions
What is key chattering?
Chattering happens when a single key press registers as multiple inputs because the switch contacts bounce unstably for a brief moment, producing an extra character or two even though you only pressed the key once. It's most common on mechanical keyboards whose switches have worn down over heavy use. This test flags it in orange whenever the same physical key fires again within 40 milliseconds.
Do results differ between a laptop keyboard and an external keyboard?
The testing method is identical either way, but the number of keys that can be registered simultaneously (rollover) is usually lower on built-in laptop keyboards than on external mechanical ones. If a specific key combination doesn't work while gaming, use the simultaneous-key count shown by this test to see your keyboard's actual limit.
Does this test work on a Mac?
Yes. When opened on a Mac, the on-screen labels automatically switch from the Windows key to ⌘ (Command) and from Alt to ⌥ (Option). Because key presses are detected by physical key position rather than the character they produce, the test stays accurate even if you're using a non-QWERTY layout like Dvorak.