Keyboard input · live combination view
Keyboard Anti-Ghosting Test
Hold several physical keys together and see which key events reach your browser. Compare combinations and the highest simultaneous count in this session.
Physical keyboard required. The diagram is a display, not an on-screen keyboard.
Not listening — activate the test area to begin.
Scroll sideways to see all keys on smaller screens.
Esc stops · Tab exits · system shortcuts may remain active
- Current combination
- No keys recorded
- Peak combination
- No keys recorded
US reference positions. Key codes outside this diagram are listed above. Esc and Tab are reserved for leaving the test.
The tool keeps only session key sets in memory and does not submit them. Site analytics may be present; the test area is marked for session-replay masking. Never enter sensitive text here.
A browser cannot detect a key event that never arrived. Compare the keys you physically hold with the highlighted keys. Missing events can be caused by the keyboard, operating system, browser or reserved shortcuts; this is not an NKRO certification.
Check a combination
- Connect a physical keyboard. Click Start listening or the test area; do not type passwords or private text.
- Hold a combination you actually use, such as W + A + left Shift + Space. Add one key at a time and compare the highlighted keys with your fingers.
- Release every key before trying a different combination. Esc ends capture; Tab ends capture and moves focus. Reset clears the session counts.
Understand what you see
Filled green keys are currently held; outlined keys have been seen since reset. The peak combination is the largest simultaneous set received, not the total number of distinct keys pressed.
If a key is missing, repeat the same combination, change the press order and try another USB connection or application. Extra reported keys may suggest ghosting; missing keys may indicate blocking. This page cannot determine the hardware cause automatically.
Keyboard testing questions
Does a high count prove N-key rollover?
No. It only shows one observed combination. Key matrices behave differently for different combinations, and system shortcuts may intercept events before the browser sees them.
Why does the diagram not match my keyboard?
The diagram shows common physical positions with US reference legends, not an automatic keyboard layout. German, Japanese, ISO and other keyboards can differ. Additional received key codes still appear in the combination text.
Can I use a phone or type with an IME?
Use a physical keyboard, including one connected to a mobile device. Touch keyboards and input methods do not provide reliable simultaneous physical-key evidence. Composition events are ignored.