Keyboard Test

Check that every key on your keyboard works. Press keys to light them up on the virtual keyboard, then check rollover, ghosting and key chatter.

Private — keystrokes never leave your device
Press any key to start

Press any key to start

Or click the keyboard. Keys are captured only while the test is active.

  • Not pressed yet
  • Held down
  • Works
  • Chatter
  • May not register
Held now
    Hold several keys at once to check rollover and ghosting.
    Keys tested 0 / 0
    Held now 0
    Most at once 0rollover
    Chatter 0double presses

    While the test is active, Tab, Space, the arrows and F-keys won’t scroll, move focus or reload the page. Hold Esc for one second, or click outside the test, to stop. Some shortcuts (Windows key combos, Alt+Tab, Ctrl+W, Fn) are handled by your computer before the browser sees them.

    Last key

    Press a key
    key
    —
    code
    —
    keyCode (legacy)
    —
    Location
    —
    Modifiers held
    —
    Lock keys
    —

    Key chatter (double press)

    50 ms

    A key that registers again within this time after you let go of it is flagged as chattering. Healthy switches never do this.

      No chatter detected so far. Type normally for a minute to check.

      Event log

      Event key code keyCode Δ ms

      Press a key to see its events here.

      How to test your keyboard

      1. Start the test. Press any letter key or click the keyboard. While the test is active, Tab, Space, the arrows and F-keys are captured instead of scrolling or reloading the page.
        The keyboard test before it starts, with the message “Press any key to start” over a faded keyboard
      2. Match your keyboard. Choose Full, TKL (no numpad) or 75%, switch between Windows and Mac labels, and turn on ISO if your keyboard has a tall Enter key and an extra key next to the left Shift.
        The TKL layout with ISO turned on: a tall Enter key and an extra key next to the left Shift, no numpad
      3. Press every key. A key turns blue while you hold it and green once it has worked. Keys tested shows how many are left.
        The virtual keyboard with most keys green, the numpad still white and Keys tested at 77 of 104
      4. Check rollover and ghosting. Hold the keys you use together — for example W, A, S, D, Shift and Space — and make sure each one lights up and nothing else does.
        W, A, S, D, Shift and Space held together: all six keys blue, listed under Held now, and Most at once showing 6
      5. Look for chatter. Type normally for a minute. A key that registers twice from one press turns orange and is listed under Key chatter, with the shortest gap between release and the extra press.
        The Last key panel showing the E key and the Key chatter panel listing E with its shortest gap in milliseconds
      6. Stop. Hold Esc for one second, click outside the test or press Stop test to give the keyboard back to the page.

      What the readings mean

      Rollover, ghosting and NKRO

      Key rollover is how many keys a keyboard can report at the same time. Basic membrane keyboards may lose a key in some three- or four-key combinations, while many gaming keyboards offer 6-key rollover (6KRO) or full n-key rollover (NKRO). Ghosting is when a key you didn’t press appears; blocking is when a pressed key doesn’t register at all.

      USB keyboards in basic (boot) mode report at most six normal keys plus modifiers. If Most at once stops at 6, check your keyboard’s software or manual for an NKRO setting.

      Keyboard not working? Fix it step by step

      1. Make sure the test is listening. If the status says Paused — click the keyboard to continue, the test stopped because you clicked outside it, scrolled it out of view or pressed Stop test. Click the keyboard drawing and press the key again.
        The keyboard test paused, with the grey status “Paused — click the keyboard to continue”
      2. Check the connection. Plug a USB keyboard into another port (directly, not through a hub), replace or charge the batteries of a wireless one, and move its receiver closer. For Bluetooth, remove the keyboard and pair it again — Windows 11: Settings › Bluetooth & devices; Mac: System Settings › Bluetooth.
      3. Clean the keys that fail. If only some keys stay white, turn the keyboard upside down, blow compressed air under the keycaps and press the key again. On a mechanical keyboard, pull the keycap and check the switch; hot-swappable switches can simply be replaced.
      4. Fix keys that type twice. A chattering key turns orange, and the event log marks the extra press with the gap in milliseconds. Clean the switch first; if your keyboard software has a debounce setting, raise it a little. If it keeps happening, the switch is worn out.
        The event log with an orange keydown row for the E key marked as chatter
      5. Wrong characters? The keyboard works, but the input language or layout is wrong — compare key and code in the Last key panel. Windows 11/10: Settings › Time & language › Language & region. Mac: System Settings › Keyboard › Text Input.
      6. Keys ignored when you type fast or briefly? Turn off Filter Keys on Windows (Settings › Accessibility › Keyboard) or Slow Keys on a Mac (System Settings › Accessibility › Keyboard).
      7. Numpad moves the cursor instead of typing numbers? Press Num Lock — the Lock keys row in the Last key panel shows whether it is on.
      8. F-keys change volume or brightness instead? Many laptops send media keys from the F-row. If F-keys stay white while keys such as AudioVolumeUp appear under Other keys detected, toggle Fn Lock (often Fn + Esc) or change the setting in the BIOS/UEFI or the keyboard’s software.
        The F-row still white while AudioVolumeMute, AudioVolumeDown, AudioVolumeUp and MediaPlayPause are listed under Other keys detected
      9. On a phone or tablet, connect a real keyboard by USB-C or Bluetooth — on-screen keyboards don’t send key codes. On a Chromebook you can also open the Diagnostics app and choose Input.
        The keyboard test on a phone with the notice “Connect a physical keyboard”

      Keys a browser can’t always see

      Some keys are handled before they reach any web page. Fn works inside the keyboard itself and never sends its own key code. System shortcuts such as Windows key combinations, Alt+Tab and Ctrl+Alt+Delete, and browser shortcuts such as Ctrl+W, Ctrl+T and Ctrl+N, are taken by the computer or browser first. On Windows, Print Screen often sends only a key release, which the test still counts. Keys that may not register are drawn with a dashed outline. In Chrome and Edge, Full screen lets the test capture more system keys, such as Esc and the Windows key.

      About this keyboard test

      This free keyboard tester runs entirely in your browser. Key presses are processed on your device and are never recorded, uploaded or stored, and the test only listens while it is active.

      It works with wired, wireless and Bluetooth keyboards — mechanical, membrane and laptop keyboards — on Windows, macOS, Linux and ChromeOS in Chrome, Edge, Firefox and Safari. In Chrome and Edge, the letters on the virtual keyboard follow your own layout, such as AZERTY or QWERTZ. Use it to check a new or second-hand keyboard, after a spill, or when a key starts to double-type.

      Frequently asked questions

      How do I test if all my keyboard keys work?

      Press every key while the test is active. Each working key turns green on the virtual keyboard, and the Keys tested counter shows how many are left. A key that stays grey after you press it is not registering.

      Why can’t the Fn key be detected?

      The Fn key is handled by the keyboard’s own firmware. It changes what other keys send, but it never sends a key code of its own, so no browser or website can detect it. To check it, hold Fn and press an F-key: if the media or brightness function works, Fn works.

      What is key chatter?

      Chatter is when a single press registers two or more times, usually because a switch is worn, dirty or damaged. The test flags a key when it registers again within the chatter threshold after you released it.

      How do I test keyboard ghosting and rollover?

      Hold several keys at once, such as the ones you use together in games. The Held now row lists every key the keyboard reports, and Most at once shows the highest number that registered together. Missing keys mean blocking; extra keys mean ghosting.

      Why don’t Print Screen or the Windows key light up?

      Your operating system may handle these keys before the browser sees them. Print Screen on Windows often sends only a key release, which still counts. In Chrome or Edge, use Full screen to capture more system keys.

      Can I test a laptop or Mac keyboard?

      Yes. Choose the 75% layout for most laptop keyboards and switch the labels to Mac for Apple keyboards, where Option and Command swap places. Keys that aren’t on the drawing are listed separately when you press them.