What this test can tell you
Highlights, history and the held-key count show keyboard events received by the page. Compare a key alone with the same key in a held combination.
Firmware and operating-system shortcuts may consume events first. A missing event or a short-interval chatter warning alone does not prove a broken switch or establish unlimited key rollover.
How to use it
- Choose the layout closest to your keyboard (full size, tenkeyless, 75% or 60%).
- Press every key once — tested keys stay green.
- Hold several keys together to check rollover and ghosting.
- Keys that stay gray after pressing are not registering.
Ghosting and rollover
Rollover describes simultaneous key presses that are reported. Blocking means a held key is missing; ghosting means an extra, unpressed key is reported. Hold gaming combinations such as W + A + Shift + Space and watch the held-key count. This checks those combinations in this browser, rather than proving every possible combination works.
Chattering keys
A worn switch can send two presses for one tap. If a key registers twice within a few milliseconds, the test flags it as possible chatter.
Keyboard ghosting and key rollover test
Key rollover is how many simultaneous presses are reported. A missing press is usually called blocking; ghosting refers to an extra key reported without being pressed. This page shows the keyboard events received by the browser, so operating-system shortcuts and firmware behavior can affect the result.
- Press each key separately first to establish that it registers on its own.
- Hold W + A, then add Shift and Space. Watch the held-key count and highlighted keys.
- Release the combination and try W + D + Shift + Space, then the actual combination used in your game.
- If a key works alone but consistently disappears in a combination, repeat in another app or on another computer before concluding that the keyboard has a rollover limit.
| What you see | What it means / next check |
|---|---|
| Every held key appears | That particular combination reaches this browser. It does not prove unlimited N-key rollover for every possible combination. |
| A key appears that you did not press | Repeat the combination slowly and inspect the key history. An extra reported key is different from a missing key or an operating-system shortcut. |
| Fn or a system shortcut is missing | The keyboard or operating system may handle it before a web page receives an event. A missing browser event alone is not evidence of a broken switch. |
Methods and sources
These explanations describe this page’s browser test and its limitations. Last updated . Reference documentation:
Not working? Try these fixes
Fn, Print Screen or media keys do not light up
These keys are handled by your operating system or keyboard firmware and are not passed to web pages. That does not mean they are broken.
Esc or Tab leaves the page or fullscreen
Tab and operating-system shortcuts normally keep their usual behavior. Where supported, Capture system keys requests browser fullscreen and Keyboard Lock so more keys can reach the test. Availability depends on browser support and permission; some keys may still be reserved.
A key does not work anywhere
Clean under the keycap, try another USB port, update the keyboard driver or firmware, and test on another computer to rule out software.
Frequently asked questions
Does it work with a Mac keyboard?
Yes. Command and Option are shown as Meta and Alt. Some Mac function keys are handled by macOS.
Does the test record what I type?
No. Key presses are shown only on this page and are not stored or sent anywhere.
Can I test a laptop keyboard?
Yes. Choose the 75% / laptop layout.