Keyboard Test

This keyboard test shows you in a few seconds whether every key on your keyboard still works. Press a key and the matching key on the diagram lights up amber while you hold it, then turns green when you release it. A key that stays dark is not reaching the computer; a key that turns red sent presses you did not make.

How to use the keyboard tester

1. Click anywhere on this page so it receives your key presses, or tap the text box on a phone or tablet with a keyboard connected.
2. Pick the diagram that matches your keyboard: Full for a desktop keyboard with a number pad, TKL for a tenkeyless board, Mac for a MacBook or Magic Keyboard, Laptop for a Windows notebook and Keypad to test only the number pad. Choose ISO if your Enter key is tall and there is an extra key next to the left Shift.
3. Press every key once, including the F row, the arrows and the modifiers. Work row by row so you do not skip any.
4. Watch the Tested counter. When it reaches the total for your layout, every key has registered at least once.
5. Press Reset to clear the diagram and run the test again, for example after cleaning a key.

Modifier keys like Shift, Ctrl and Alt are tested on their own, so you do not need to hold anything while you press them. Holding Ctrl or Cmd with a letter is treated as a shortcut by the browser and is not blocked, so avoid combinations such as Ctrl+W or Cmd+Q during the test.

What each key colour means

• A
  Not pressed yet

  The test has not seen this key. Press it.

• A
  Held

  The key-down event arrived and the key is still down.

• A
  Works

  The key was pressed and released cleanly at least once.

• A
  Chatter or stuck

  Pressed again within 25 ms of being released, which only a bouncing switch can do, or held for more than three seconds without a release.

• Fn
  Not visible to browsers

  Fn is handled inside the keyboard and never reaches the page. It is drawn so the layout looks right, but it cannot be tested here.

Hover over any key on a desktop to see its KeyboardEvent.code and how many times it has been pressed. The log under the keyboard lists the most recent presses with the time each key was held, in milliseconds, which is useful when you are comparing a suspect key with a healthy one.

What the keyboard test checks

Keys that do not register

If you press a key and nothing changes on the diagram, the keyboard did not send a key-down event. On a wired keyboard that usually points to a dirty or worn switch, a damaged membrane, or a broken trace in the circuit under that key. On a wireless keyboard, check the battery and the receiver before blaming the key: a weak link drops individual presses in a way that looks exactly like a dead switch.

A whole row or column that fails together is almost never five broken switches. Keyboards wire keys in a matrix, and a single bad connection on one line takes out every key on it. The same symptom after a liquid spill means the board needs drying or cleaning rather than new switches.

Keys that chatter

Mechanical switches wear out by bouncing: one press makes contact, breaks it, and makes it again a few milliseconds later, and the computer sees two presses. This is called chatter, and it is why a worn key types "tthe" instead of "the". The test treats a second press that arrives within 25 ms of the release as chatter, because a finger cannot move that fast, and turns the key red. The log entry for the extra press is labelled chatter so you can see how often it happens. The usual fixes are blowing out the switch, cleaning it with contact cleaner, or replacing it on a hot-swap board.

Holding a key down makes the operating system repeat it, which is normal and is not flagged. The red state is reserved for presses the keyboard itself invented.

Keys that stick

A key that stays amber after you let go has not sent its release. Debris under the keycap, a bent stabiliser on a wide key such as Space or Backspace, or a switch that physically jams can all cause it. After three seconds the key turns red and counts as an issue. On some laptops a key that only sticks when warm points to the keyboard flexing against the chassis.

Modifier and system keys

Shift, Ctrl, Alt, Cmd and Option report like any other key here, so you can confirm each one individually. A few keys are taken by the operating system before the browser sees them: the Windows key opens the Start menu, F11 toggles full screen, Print Screen takes a screenshot on Windows and only reports when it is released, and keyboard media keys change the volume or brightness instead of reaching the page. The Fn key never leaves the keyboard at all. If one of these keys stays dark, that is expected and not a fault. To check Fn, press Fn together with a function key and watch whether the system responds, for example by changing the volume.

Ghosting and rollover

The Max at once counter records the largest number of keys the test has seen held at the same time. Press a chord of several keys and compare that number with how many fingers are down. If it tops out at two or three while you are holding six, the keyboard is ghosting or has limited rollover. The keyboard ghosting test is built for exactly this check and shows which combinations drop out.

When to run a keyboard test

• Before you blame software. If a key stops working in one program, test it here first. A key that lights up in the browser is fine, and the problem is a shortcut, a language setting or the application itself.
• After cleaning or a spill. Run the full test to make sure every key came back, not just the ones you noticed.
• Buying or selling second-hand. A two-minute pass over every key is the quickest way to prove a used keyboard or laptop is fully working.
• Before a warranty claim. Note which keys fail and how, so you can describe the fault precisely.
• Checking a new mechanical board. Hot-swap boards occasionally ship with a switch not seated properly. A dark key on the diagram tells you which one to reseat.

Which keyboard test do you need?

The home page checks that every key registers. The tests below look at one aspect in more depth, each with its own tool.

• Keyboard latency test measures your reaction time to a prompt, how long you hold each key and how fast auto-repeat runs, so you can compare two keyboards side by side.
• Keyboard ghosting test counts how many keys register at once and finds the combinations that drop out.
• Mac keyboard test opens the Mac layout directly, with notes on Fn, Touch ID and the keys macOS handles itself.
• What key am I pressing shows the key name, code and location of every press, which is handy for remapping and for keys with worn-off labels.
• Keypad test tests the number pad with Num Lock on and off.
• Laptop keyboard test uses a compact layout and explains the Fn combinations on notebook keyboards.
• Keyboard keys not working walks through the fixes once the test has found a problem, from drivers to cleaning to replacement.