How this keyboard test works
Click anywhere on the page and start pressing keys. Each key you press lights up on the on-screen ANSI keyboard and stays marked, so after a pass over the whole keyboard you can see at a glance which keys never registered. For the latest key you also get its e.key, e.code and keyCode values, a press counter and a key history list.
The rollover test shows the maximum number of keys held down at the same time. Press and hold as many keys as you can; the page records the highest count. This is how you check N-key rollover (anti-ghosting): a gaming keyboard should register all the keys you press, while a basic office board may stop at 3 to 6 keys. On a phone or tablet, the test works with an on-screen keyboard too.
Everything is handled in your browser. Keystrokes are not logged, sent or saved anywhere, and the history disappears when you close the tab.
How to read the results
- Unlit keys. A key that never lights up either does not register or is intercepted by the system (see below). Try it several times with different pressure.
- e.code vs e.key.
e.codenames the physical key position, such asKeyA.e.keyis the character it produces, such asaorqon an AZERTY layout. If these do not match what you expect, the keyboard layout set in your operating system differs from the physical keyboard. - Double entries. If one press increases the counter by two, the switch is chattering. Cleaning or replacing the switch may fix it.
- Rollover. Typing alone needs only a few keys. Gaming combos such as moving diagonally, jumping and using an ability need more. If a key stops registering when you add another, you have found ghosting or a rollover limit.
- System keys. Some keys (Windows key, Print Screen, media keys, Fn) are captured by the operating system or never sent to the browser. Absence of a reaction is not always a fault.
Keyboard not working? Try these fixes
- Check for a stuck key. If a key shows as pressed all the time, tap it a few times. On a laptop, shut down and press the key firmly, then clean around it with compressed air.
- Fn lock and Num Lock. If the F-keys trigger volume or brightness, toggle Fn Lock (often Fn + Esc). If the number pad moves the cursor, press Num Lock.
- Layout mismatch. On Windows 11 check Settings → Time & language → Language & region → Keyboard. On macOS see System Settings → Keyboard → Input Sources. Wrong layouts swap symbols such as @ and ".
- Turn off Filter Keys and Sticky Keys. Windows can ignore brief or repeated presses. Open Settings → Accessibility → Keyboard and disable Sticky keys, Filter keys and Toggle keys.
- Laptop keyboard disabled. In Device Manager, expand Keyboards, right-click the built-in keyboard and choose Enable device or reinstall the driver, then restart.
- External keyboards. Change the USB port, replace batteries, and re-pair Bluetooth. Test with another cable if you have one.
- Chromebook and Mac. Reset the keyboard layout in settings and test in a guest session to exclude extensions.
Why test your keyboard
A keyboard test is the quickest way to find a dead key before you return a laptop, buy a used keyboard or start a long game session. It also proves whether a typing problem comes from hardware or from settings, and shows if a new gaming keyboard really delivers the rollover it advertises.
Frequently asked questions
What is N-key rollover?
It is the number of keys a keyboard can register at once. Full N-key rollover registers every key you press, while basic boards may only handle 3 to 6.
What is keyboard ghosting?
Ghosting happens when a keyboard fails to register some keys, or registers phantom ones, when several are pressed at the same time. The rollover test on this page shows the highest number of simultaneous keys detected.
Why are some keys not lighting up?
The key may be broken, blocked by dirt, or captured by the operating system, like the Windows key or media keys. Try pressing it harder and test in another app.
Why does my keyboard type the wrong characters?
The keyboard layout in your operating system probably does not match your physical keyboard. Change the input source or layout in system settings.
What is the difference between key and code?
The code is the physical key position, for example KeyA. The key is the character it types, which depends on layout and modifier keys like Shift.
Is anything I type here saved?
No. Key presses are handled only in your browser and are not stored or sent anywhere.
Why don't Fn, Print Screen or media keys light up?
The Fn key is usually handled by the keyboard hardware and never reaches the browser. Print Screen and media keys may be intercepted by the operating system, so the browser may not receive them, which does not mean the keys are broken.
What is the difference between ANSI, ISO and JIS layouts?
ANSI is the US layout with a wide Enter key and a long left Shift. ISO has a tall Enter key, an extra key next to the short left Shift and an AltGr key, and JIS adds extra keys for Japanese input around the space bar.