Keyboard Tester
A keyboard tester detects which keys on your keyboard are registering correctly in real time. Press any key and it lights up on the on-screen layout — helping you find stuck keys, diagnose keyboard ghosting, and verify your keyboard's N-key rollover (NKRO) count. Works on any USB, Bluetooth, or laptop keyboard. No download required.
0
Keys Held
0
Max Simultaneous
0/74
Keys Tested
0%
Coverage
Press any key to test it. Blue = held, Green = tested.
How to Test Your Keyboard
Press Each Key
Tap every key individually. Blue = currently held, Green = tested and released. Any key that stays dark after pressing may be broken or stuck.
Test Rollover
Hold W + A + Shift + Space simultaneously. The 'Keys Held Now' counter shows how many keys are registered at once — the higher, the better for gaming.
Check Your Score
The progress bar tracks what percentage of all keys you've tested. Aim for 100% to confirm every key works before a gaming session or purchase return.
What Is a Good N-Key Rollover Score for Gaming?
Rollover determines how many simultaneous keypresses your keyboard can register without dropping inputs. Most gaming actions use 3–5 keys at once (WASD + Shift + Space). The table below shows what each rollover level means in practice.
| Rollover | Keys at Once | Typical Keyboard | Gaming Verdict |
|---|---|---|---|
| 2KRO | 2 | Budget membrane | ❌ Not suitable |
| 6KRO | 6 | Most gaming keyboards | ✅ Sufficient for most games |
| NKRO (USB) | 14–18 | Mid-range mechanical | ✅ Excellent |
| NKRO (PS/2) | Unlimited | High-end mechanical | ✅ Best possible |
Frequently Asked Questions
How do I use the keyboard tester?
Simply press any key on your physical keyboard. The corresponding key on the on-screen layout will light up blue while held and turn green once released, confirming it was detected. No clicks or setup required — just start typing.
What is N-key rollover (NKRO)?
N-key rollover means the keyboard can register an unlimited number of keys pressed simultaneously without any being dropped or missed. The 'N' stands for any number. Gaming keyboards often advertise 6KRO (6-key rollover) or full NKRO. To test yours, hold down as many keys as possible and watch the 'Keys Held Now' counter — if it stops increasing before all your keys are held, you've found the rollover limit.
What is keyboard ghosting?
Keyboard ghosting is when a keypress is not registered because too many other keys are held at the same time, or because certain key combinations interfere with each other. It happens due to the electrical matrix design of budget keyboards. NKRO keyboards eliminate ghosting by using a separate circuit per key. You can test for ghosting using our tester by holding common gaming key combos like W + A + Shift + Space.
How do I test for stuck or broken keys?
Press every key individually across the full keyboard layout. Any key that does not light up green after being pressed is either stuck (registered as always-pressed before you even touch it) or broken (not registering at all). The 'Keys Tested' counter tracks your progress so you can ensure every single key has been verified.
Why is my keyboard not detected by the tester?
The tester listens for key events in your browser. Some keys are captured at the OS level and never reach the browser — these include PrintScreen, some media keys, and function keys that trigger OS shortcuts. Make sure the page is in focus (click on it once) before testing. If a key still doesn't register, it may be a hardware fault.
Does the keyboard tester work with gaming keyboards?
Yes. The tester works with any keyboard your OS can read — mechanical, membrane, gaming, laptop, or Bluetooth. It reads raw key codes directly, so even custom layouts and gaming keypads will work as long as your OS recognises the keypress.
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