Input Lab · guided key-combination checks

Keyboard Ghosting Test

Test common gaming clusters and document which simultaneous key combinations your browser actually receives.

Guided combination labKeyboard events · local session
Test paused. Start when you are ready.
Physical code
Reported key
Active now0
Session maximum0
Esc1234567890MinusEqualBack
TabQWERTYUIOPBracket LBracket RBackslash
CapsASDFGHJKLSemicolonQuoteEnter
Shift LZXCVBNMCommaPeriodSlashShift R
Ctrl LMeta LAlt LSpaceAlt RCtrl R LUpDown R
Choose a cluster, hold every shown key for two seconds, then release them together.

How to use: Keyboard Ghosting Test

Start the test and select a suggested gaming cluster.

Hold the displayed keys together for two seconds, then release them.

Repeat the failed combination and record the physical cluster—not only the characters.

What the result actually measures

The guided flow compares the keys you intend to hold with the keydown/keyup events delivered to the page. It focuses on realistic movement, sprint, crouch, ability and number-row combinations.

Measurement boundary: Ghosting behavior depends on the keyboard matrix and exact combination. Passing several clusters does not prove every combination will register, and reserved browser shortcuts cannot be tested reliably.

How to interpret the output

All intended keys observed

The selected combination reached the browser in this environment. Test the specific combinations used by your games as well.

One key missing

Repeat slowly. If the same physical key disappears only in that combination, keyboard matrix blocking is a possible cause.

Unexpected extra key

True ghosting can create an unintended key, although modern keyboards more often block a key instead. Confirm outside the browser if possible.

Troubleshooting unexpected results

The page scrolls or opens a shortcut

Avoid reserved combinations and use the provided clusters. Some actions cannot be captured safely by a webpage.

Laptop and external keyboard differ

They use different matrices and controllers. Test and document them separately.

Frequently asked questions

What is keyboard ghosting?

It is an incorrect or missing result when several keys in a keyboard matrix are pressed together. Anti-ghosting designs reduce or block these conflicts.

What is N-key rollover?

NKRO describes the ability to register many simultaneous keys independently. A browser test can observe selected combinations but not certify the entire matrix.

Why test physical codes?

Physical positions stay meaningful across language layouts and match how gaming controls are arranged.