Keyboard Ghosting Test and Key Rollover Checker
Hold several keys at once and see which ones your keyboard actually sends. The counter shows the most keys registered together, so you can check gaming combos and anti-ghosting claims.
- 100% free
- No sign-up
- Runs in your browser
- Updated October 2026
On a phone or tablet, connect a USB (OTG) or Bluetooth keyboard first. The on-screen phone keyboard does not send real key presses, so it can't be tested here.
Press every key once. Blue = held down now, green = works, orange = typed twice by itself, red = held too long (may be stuck). While this area is focused, keys like Tab, Space and F5 stay on the page; click outside it to stop.
Last key
- key
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- code
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- keyCode
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- Side
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- Held for
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Other keys found
Media, volume and language keys that are not on the drawing show up here.
Problems found
- None yet. Type a sentence to check for double letters.
Not pressed yet
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How to test ghosting and key rollover
Hold several keys together and watch "Held at once". If a key you hold stays white, the keyboard dropped it (ghosting). Try the combos games use: W+A+Shift+Space, or Q+W+E+R. Many laptop and office keyboards register only 2 to 6 keys at once in some combinations, which is normal for them.
Ghosting, blocking and rollover in plain words
Inside most keyboards, keys sit on a grid of shared wires. Reading one or two keys is easy. When you hold three or four keys that share wires, the keyboard can't always tell which ones are really down. Good keyboards then simply ignore the extra key, which is called blocking or jamming. Older designs could even report a key you never pressed, which is true ghosting. Today most people use "ghosting" for both.
Key rollover is the number of keys a keyboard promises to read at the same time. 2-key rollover is common on office keyboards and many laptops. Gaming keyboards often advertise 6-key rollover or N-key rollover, where every key counts.
How to test ghosting with this tool
- Click the drawn keyboard once so the page receives the keys.
- Press and hold your first key, then add keys one at a time without letting go.
- Every key you are holding should be blue. Held at once shows how many are down right now, and Most keeps the record.
- If you add a key and it stays white, the keyboard dropped it in that combination. Try the same number of keys in a different spot to compare.
Combinations worth trying
| Use | Keys to hold together |
|---|---|
| Running and jumping in games | W + A + Shift + Space |
| Strafing while crouching | A + S + Ctrl + Space |
| Ability keys | Q + W + E + R |
| Two players on one keyboard | W + A + D + Up + Left + Right arrows |
| Fast typing rolls | The letters of common words such as "the" and "and" held together |
Many inexpensive keyboards handle W, A and Space together but fail when Shift is added, or struggle with arrow keys plus letters. Knowing your keyboard's weak combinations lets you remap game controls to ones that work.
Reading the result
- Most stays at 2 or 3: a typical office or laptop keyboard. Fine for typing, limiting for some games.
- Most reaches 6: common for USB keyboards with 6-key rollover. Enough for nearly every game.
- Most goes beyond 6 with every combination: the keyboard is behaving like N-key rollover.
Modifier keys behave a little differently. Shift, Ctrl, Alt and the Windows key usually have their own wiring, so they rarely ghost. The browser and the operating system may still hold back some combinations, such as those with the Windows key, so try Full screen if a modifier combo seems missing.
Ghosting is not the same as a broken key
A key that fails only in big combinations is a design limit. A key that fails on its own, types twice or gets stuck is a fault, and the orange and red warnings on the drawing will show it. If you are testing a keyboard before buying, check both: rollover for gaming, and every single key for faults. Use the mic test for your gaming headset, and find more checks on the phone and device tests page.
Other keyboard test pages
Need more options? Open the full Keyboard Test Online.
Frequently asked questions
What is keyboard ghosting?
Ghosting is when you hold several keys together and one of them doesn't register, or a key you didn't press seems to. It happens because cheaper keyboards share wiring between keys, so some combinations can't be read at the same time.
How do I test for ghosting?
Click the drawn keyboard, then hold down the keys you use together, for example W, A, Shift and Space. Every key held should turn blue. If one you are holding stays white, that combination ghosts on your keyboard.
What is N-key rollover?
N-key rollover (NKRO) means every key can be read at the same time, however many you press. 6-key rollover means at least six keys at once. Many office keyboards guarantee only two keys in some combinations.
Why does my gaming keyboard show fewer keys than advertised?
Some keyboards switch to full rollover only in a special mode or over a particular connection. Also, the system may hold back combinations such as Win key shortcuts. Check the keyboard's manual or software for an NKRO setting and test again.
Is ghosting a fault?
Usually not. It's a design limit of the keyboard's wiring. A fault looks different: a key that never works on its own, or one that types twice. The main keyboard test on this page checks for those.