NKRO test
Hold as many keys as you can. The count shows how many register at once and whether you have 6-key or n-key rollover.
NKRO test workspace
How to use
4 short steps.
Hold a few letters first
Press and hold three or four letter keys. Held now should match the number of keys you are holding.
Keep adding keys
Without letting go, press more letters with your other hand. Rest a palm across a row to hold more than you have fingers.
Read the largest count
Most at once keeps the biggest set you held. Six is the usual limit for 6-key mode; more shows n-key rollover.
Count letters, not modifiers
Shift, Ctrl, and Alt are counted separately by most keyboards. Use letters, numbers, and Space when you push for the maximum.
What the result means
Match what you see to one of these.
If the count passes 6, you have n-key rollover
If Most at once reaches 7 or more with letters only, the keyboard reports every key you hold. It is running in NKRO mode on this connection.
If the count stops at exactly 6, the keyboard is in 6-key mode
If you clearly hold more than six letters and only six light, the keyboard or its connection is limited to 6-key rollover. Many boards default to this for compatibility, and Bluetooth usually enforces it.
If the count stops below 6, look for blocking
If a fourth or fifth key refuses to light, the keyboard matrix is blocking that combination. Use the ghosting test to find which keys clash.
Troubleshooting
If the test fails, try these in order.
Connect by cable
Bluetooth and some wireless receivers cap rollover at six. Plug in with USB and hold the same keys again.
Turn on NKRO in the keyboard
Many boards toggle it with Fn+N or a switch in the maker's software. Some call it gaming mode. Enable it, then hold the keys again.
Leave BIOS or compatibility mode
A compatibility or BIOS mode forces 6-key reports so the keyboard works in firmware menus. Switch it off and hold the keys again.
Retest with letters only
Drop Shift, Ctrl, and Alt from the chord, since they are counted separately. Hold letters, numbers, and Space and read the count again.
What this test can't tell you
Where a browser check stops.
- The count is the largest set the browser received in this session, not the manufacturer's rating, and a shortcut taken by the system lowers it.
- The page cannot read the USB report mode or firmware setting. It only shows how many keys reached the browser together.
FAQ
Common questions about this test.
How do I tell if my keyboard has n-key rollover?
Hold more than six letter keys at once. If Most at once passes 6, the keyboard has n-key rollover on this connection. If it stops at 6, it is running in 6-key mode or does not support more.
How do I enable NKRO?
Check the manual for a key combination such as Fn+N, or a toggle in the maker's software. Use a wired USB connection, since Bluetooth is usually limited to six keys, and turn off any BIOS or compatibility mode.
Is 6-key rollover enough?
For typing and most games, yes. Fast typists rarely hold more than three keys, and most games need four or five. Rhythm games, chorded input, and some fighting games are where six becomes a limit.
What does 6KRO mean?
The keyboard reports up to six ordinary keys plus modifiers such as Shift and Ctrl at the same time. It comes from the standard USB keyboard report, which has six key slots. A seventh key is dropped until one is released.
Is n-key rollover necessary?
No. It removes a limit you may never reach. It matters if you play games that hold many keys at once or use chorded shortcuts, and it usually comes with a full anti-ghosting matrix.