Keyboard Tester
Press any key on your keyboard to check it’s working. Each key lights up on the diagram below the moment it registers.
Click anywhere here, then start pressing keys
What is a keyboard tester?
A keyboard tester is a simple diagnostic tool that shows you, in real time, whether each key on your keyboard is sending the correct signal to your computer. Instead of guessing whether a key is broken, unresponsive, or double-pressing, you just press it here and watch it light up on the on-screen diagram — no installation required.
How to test your keyboard for stuck or broken keys
Click into the focus area above, then methodically press every key on your physical keyboard, row by row. Any key that lights up correctly is registering properly. If a key doesn’t light up at all, or lights up a different key than the one you pressed, that’s a sign of a wiring fault, a stuck key, or a keyboard driver issue.
What is key rollover and why does it matter?
| Term | What it means |
|---|---|
| Key rollover | How many keys a keyboard can register accurately at the same time |
| Ghosting | When pressing multiple keys causes an unintended key to register, or one to be dropped |
| N-key rollover (NKRO) | A keyboard that can register unlimited simultaneous keypresses correctly — common on gaming keyboards |
| 6-key rollover (6KRO) | A common USB limit allowing up to 6 non-modifier keys at once, standard on most office keyboards |
The “Keys Held Now” counter above updates live, so you can hold down several keys at once to see how many your keyboard and browser correctly register simultaneously.
Common keyboard problems this tool can help diagnose
- Unresponsive keys: a key that doesn’t light up at all usually points to a hardware fault.
- Wrong key registering: if pressing one key lights up a different one, check for a stuck key nearby or a keyboard layout/language mismatch in your OS settings.
- Double inputs: a single press that registers twice usually means a worn-out switch that needs cleaning or replacing.
- Ghosting under multiple presses: if combinations of keys (like gaming WASD + Shift) don’t register together, your keyboard may have a lower rollover limit than you need.
Frequently asked questions
Does this work with a laptop’s built-in keyboard?
Yes, it works with any physical keyboard connected to or built into your device, including laptops.
Can I test a virtual/on-screen keyboard with this?
This tool is built for physical keyboards. On-screen/touch keyboards on phones and tablets don’t send the same key events, so results may be unreliable there.
Is my keystroke data stored anywhere?
No. Every keypress is processed locally in your browser only — nothing is recorded, saved, or sent anywhere.
Why do some keys show unusual names?
Keys like Meta, Control, or Alt are labeled using their technical key names rather than the printed symbol, since that’s what your operating system actually reports.
