UtilityBaseDevice Tests
Keyboard Rollover / NKRO Test
Find how many keys your keyboard registers at once — 6KRO or full NKRO.
Updated July 10, 2026
How to use the keyboard rollover / nkro test
- 1Click into the page, then hold several keys at once.
- 2Add more keys and watch the simultaneous count.
- 3Note the maximum you can register.
- 4Try clusters you actually use, like WASD plus space and shift.
Common uses
- Testing whether a keyboard supports NKRO
- Checking for ghosting on key combinations you game with
- Comparing rollover before buying a keyboard
- Confirming a mechanical keyboard's advertised NKRO
Frequently asked questions
What is key rollover?
Rollover is how many keys a keyboard can report pressed at the same time. 6-key rollover (6KRO) registers up to six simultaneous keys plus modifiers; N-key rollover (NKRO) registers every key independently, no matter how many you hold. It matters for fast typing and gaming where you press several keys at once.
What is keyboard ghosting?
Ghosting is when a keyboard fails to register a key because too many others in the same wiring matrix are already pressed — a classic limit of cheaper membrane boards, where certain three-key combos block a fourth. NKRO keyboards use a design that prevents it, so every combination works.
Why did a key not register in the test?
Two reasons. Your keyboard may genuinely cap at that many keys, or the browser and operating system intercept certain combinations (like some function and system shortcuts) before the page sees them. So an occasional key can fail to appear even on a full NKRO keyboard.
About this tool
The keyboard rollover test measures how many keys your keyboard can register simultaneously. Hold as many keys as you can and it counts the current and maximum simultaneous keydowns, telling you whether you hit a 6-key ceiling or reach the 7-plus that indicates N-key rollover. Cheap keyboards often cap at 6KRO or suffer ghosting, where some three-key combinations block a fourth; gaming keyboards advertise NKRO so every key is independent. A few combinations are intercepted by the browser or OS, so an occasional key may not register even on a good board. Runs locally in your browser.
Like most tools on UtilityBase, the keyboard rollover / nkro test runs entirely in your browser — nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more device tests here.
Was this tool helpful?
Related tools
Keyboard Tester
Press any key to see it light up — find dead keys and check key codes.
Device Tests
Typing Speed Test
Test your WPM and accuracy with a 30 or 60 second typing challenge.
Productivity Tools
Mouse Double-Click Test
Detect a chattering mouse switch by timing the gap between your clicks.
Device Tests
Gamepad Tester
Test every button, trigger, and stick on your controller — with stick drift detection.
Device Tests
Microphone Tester
Check your mic with a live level meter — nothing is recorded.
Device Tests
Internet Speed Test
Download, upload, latency, and jitter — measured to a real CDN edge.
Device Tests