Keyboard Tester

How to test your keyboard

1. Press Start test, or click the on-screen keyboard. A coloured border shows that the test area has focus.
2. Press every key you want to check. The matching key lights up while it is held and stays tinted once it has been tested.
3. Watch Keys tested go up, and look for keys that never light up: they may not be working.
4. Read the details of each press under Last key, and the recent history in the Event log.
5. To test rollover, hold down several keys at the same time and read Max keys at once.
6. Press Reset to start over. Click anywhere outside the test area to give the keyboard back to the page.

While the test area has focus, this tool blocks the default action of the keys, so Tab, the arrow keys, Backspace and shortcuts like Ctrl+S or Ctrl+F can be tested without scrolling or leaving the page. A few system shortcuts are handled by the operating system before the browser sees them (for example Ctrl+Alt+Del, Alt+Tab, the Windows key on its own in some setups, or Cmd+Tab on a Mac), so they can’t be captured.

Layouts: QWERTY, AZERTY and others

The on-screen keyboard is a full-size US QWERTY layout with 104 keys. Keys are matched by their physical position, the code value, not by the character they type. On a French AZERTY keyboard, pressing the key labelled A lights up the key in the Q position, because code is “KeyQ” whatever the layout. After you press a key, its legend changes to the character your layout produced, so the picture quickly matches your own keyboard. Keys that don’t exist on this layout, such as the extra key next to the left Shift on ISO keyboards (IntlBackslash) or media keys, appear under Keys not on this layout.

key, code and location explained

• key is the character or action produced, taking the layout and modifiers into account: “a”, “A”, “é”, “Enter”, “ArrowLeft”.
• code identifies the physical key: “KeyA”, “Digit1”, “ShiftLeft”, “Numpad5”. Games and shortcuts that depend on position use it.
• location tells apart keys that exist twice: 0 for standard keys, 1 for the left version (left Shift, Ctrl, Alt), 2 for the right version, and 3 for the numeric keypad.
• keyCode is the older numeric code, deprecated but still used by some software.

Rollover, ghosting, stuck keys and double registrations

N-key rollover is the number of keys a keyboard can register at once. Many office keyboards manage only 2 or 3 keys in some combinations: extra keys are ignored, or a wrong key appears (ghosting). Gaming keyboards often advertise 6-key rollover or full N-key rollover. Try the combinations you really use, such as W, A, Shift and Space together.

A key held for more than 2 seconds is listed under Possibly stuck and shown in red. If you aren’t pressing it, the key cap or switch may be jammed, or a key was released while the focus was elsewhere.

Double registrations lists keys pressed again less than 40 ms after being released. Nobody types that fast on purpose, so it usually means a worn or dirty switch that “chatters” and types letters twice.