Keyboard Test

How to test your keyboard

1. Click anywhere on this page so it has focus, then press each key once. Every key that is detected turns green.
2. Watch for keys that stay grey (not detected), keys that stay blue after you let go (stuck), and keys outlined in amber (they triggered twice from one press).
3. Hold several keys together, such as W, A, S, D and Space, and check the Most at once counter to test rollover.
4. Use Hide number pad for laptops and compact keyboards, and Show Mac labels for Apple keyboards.
5. Press Reset to start again, for example after cleaning a key.

The tester uses the key’s physical position, so it works with any language layout. If your keyboard has keys that aren’t on the picture, such as media keys or the extra key found on UK and European keyboards, they appear under Other keys detected.

Reading the results

• Green: the key was detected at least once. A key that turns green when you press it is working electrically.
• Blue: the key is down right now. If a key stays blue after you release it, it may be physically stuck, or the keyboard may have missed the release.
• Amber outline: the key re-triggered less than 35 ms after release. One or two flags during very fast typing can happen, but repeated flags on the same key point to key chatter, the cause of double letters.
• Grey after pressing: the key wasn’t detected. Press it firmly in the center; if it still stays grey, see the fixes below.
• keyCode and Code: technical values for developers and for checking remapping software. Code names the physical key (for example KeyA), while Key shows what your layout produces.

Keys a browser can’t fully test

Some keys are handled by the keyboard or the operating system before any website sees them:

• Fn is processed inside the keyboard on nearly all laptops and compact keyboards, so it can’t be detected by any software.
• Print Screen on Windows only reports the release, so it lights up when you let go.
• Windows key, Command, Alt+Tab, Ctrl+Alt+Delete and similar shortcuts may trigger system actions. In Chrome and Edge, use Full screen to capture Esc and most of these keys; system-level combinations such as Ctrl+Alt+Delete are always reserved.
• Media, volume and brightness keys are often handled by the system or keyboard software. If the action happens (for example, the volume changes), the key works.

Keyboard keys not working? What to try

One key or a few keys don’t respond

• Turn the keyboard upside down and tap it gently, then blow compressed air under the key at an angle. Crumbs and dust are the most common cause.
• On mechanical keyboards, remove the keycap with a keycap puller and check the switch. Hot-swappable boards let you replace a faulty switch in seconds.
• If the same key fails on a second computer, the fault is in the keyboard; if it works there, look at software or settings on the first computer.

The whole keyboard or a whole area doesn’t work

• Number pad dead? Press Num Lock. With Num Lock off, the number keys act as arrow and navigation keys.
• Wired keyboard: plug it directly into the computer instead of a hub or monitor port, and try another USB port.
• Wireless or Bluetooth: replace or charge the batteries, move the receiver closer (a USB extension helps), and re-pair the keyboard.
• Windows: in Device Manager, expand Keyboards, uninstall the device, then restart so Windows reinstalls the driver.
• Laptop: some laptops have a keyboard lock or Fn lock shortcut. Check your laptop maker’s key guide, and install the latest keyboard or chipset driver.

Keys need to be held, or repeat too fast or too slow

• Windows: turn off Filter keys in Settings › Accessibility › Keyboard. Filter keys makes Windows ignore short presses, which feels like a broken keyboard. Turn off Sticky keys there too if modifier keys seem to stay pressed.
• Mac: check System Settings › Accessibility › Keyboard for Slow Keys and Sticky Keys, and adjust repeat speed in System Settings › Keyboard.

Letters type twice (key chatter)

• Confirm it here: press the key slowly 20 times and watch for amber flags.
• Clean the switch with compressed air while pressing the key repeatedly.
• On mechanical keyboards, replace the switch, or raise the debounce time in the keyboard’s software if it has that setting.
• Under warranty? A chattering key is a hardware fault, and the test result is good evidence for a claim.

Ghosting and rollover explained

Keyboards detect keys through a grid of wires. Cheaper designs share wires between keys, so pressing certain combinations can make the keyboard register an extra key that you didn’t press (ghosting), or ignore one of the keys (blocking). To prevent ghosting, most keyboards block the combination instead, which is why a game may ignore a key while you hold others.

To test, hold keys you actually use together. Gamers should try their movement keys plus Shift, Ctrl and Space, while musicians and stenographers may need far more. If the Most at once number stops rising while you add keys, you have found your keyboard’s limit for that combination. A keyboard sold as “N-key rollover” should keep counting for every key you can hold down. Keep in mind that USB keyboards in compatibility mode may report a maximum of six keys plus modifiers.

Frequently asked questions