Multi-key rollover check
Keyboard Ghosting Test
Hold several keys at once to see which combinations the browser receives and whether your keyboard drops an input.
Keyboard Ghosting Test
Click here, then press Space
If a physically held key is missing here, the keyboard, connection, operating system, or a reserved shortcut may be blocking that combination.
What this tool measures
Ghosting happens when a keyboard matrix cannot report every key in a combination. The test shows only the key events that reach the browser.
How to use it
- Focus the capture area.
- Hold any combination you actually use in a game or application.
- Check that every held key remains listed at the same time.
Useful keyboard combinations to test
- W + Shift + Space for moving, sprinting, and jumping
- W + A or D + number keys for movement and abilities
- Ctrl + Alt + letter keys for application shortcuts
Identifying missing key combinations
Every physically held key should remain visible. If one is absent, that key event did not reach the browser.
Repeat the test
Use several runs under the same conditions before drawing a conclusion from a single value.
Compare like with like
Keep the browser, window size, device connection, and power mode consistent when comparing results.
Test combinations you actually use
Prioritize shortcuts and game combinations from real use instead of chasing the highest possible simultaneous-key count.
Exclude system shortcuts
Alt+Tab, operating-system keys, and other reserved combinations may be intercepted before the browser sees them.
Measurement limits
Operating-system shortcuts and browser-reserved combinations may be intercepted before a web page can read them.
Privacy
Measurements are calculated locally in your browser and are not uploaded by the tool.
What to check when a keyboard input is missing
Keep the page active
Background-tab throttling, browser extensions, and other busy applications can affect browser measurements.
Retest under controlled conditions
Reload the page, keep the same settings, and repeat the measurement before treating an outlier as a fault.
Change the connection
Try a motherboard USB port, wired mode, or a different wireless mode before judging the keyboard matrix.
Check keyboard and macro software
Keyboard utilities, macros, remapping, and system shortcuts can intercept or change key events.
Keyboard rollover questions
Can a browser see every key?
No. Reserved system keys, function layers, and some firmware behavior may never appear as ordinary web key events.
Where is the test data processed?
The measurement is calculated in this browser tab and the tool does not upload the raw test input.
What do 6KRO and NKRO mean?
6KRO commonly means six ordinary keys can be reported together; NKRO describes a much higher or near-full rollover capability.