Keyboard Tester

Common questions

Which keys cannot be tested in a browser?

Fn, Power and most media and brightness keys are handled in the keyboard's own firmware or by the operating system, so no key event ever reaches a web page. The Mac layout draws fn with a dashed outline for exactly this reason and leaves it out of the tested count, so it cannot make a working keyboard look faulty. A few combinations are reserved too: Cmd or Ctrl with W, T, Q and Tab are taken by the browser or the system before the page is told about them. Everything else, including every letter, modifier, arrow, function key and number pad key, reports normally.

Why does F11 not go full screen here?

Because the tool holds it back on purpose. Once you have engaged with it, by pressing a key or clicking the board, it suppresses the default action of F1 to F12, Tab, Space, Backspace, slash and apostrophe, so F5 cannot reload the page mid-test, Space cannot scroll the board off screen and Tab cannot jump focus away from it. Three things are never held back: anything with a Cmd or Win key down, Shift with Tab, which is how focus moves back out, and any key pressed while the cursor is in a text box or on a button. Ctrl is not exempt, so Ctrl with F5 or Ctrl with Space is held back the same as the bare key, and the browser still wins on anything it reserves for itself. Press Esc, anywhere except the typing box, to hand the keyboard back. The table under the tool lists every key it suppresses and every combination it is not allowed to touch.

What does rollover mean?

Rollover is the most keys the browser saw held down at the same moment. Press four or five keys together and the figure climbs; on many membrane keyboards it stops climbing around six, or stalls on particular combinations, because the switch matrix cannot tell some simultaneous presses apart. That ceiling is real and it is what gamers mean by n-key rollover. Read it as a floor rather than a specification, though: the operating system and the browser can each drop a key event, so the number is the most this page actually saw, not the most your hardware can do.

Does it work for a laptop keyboard or a Mac?

Yes. Pick ANSI for a US board, ISO for a UK or European one, which has the extra key beside the left Shift and the hash key next to the apostrophe, or Mac for Command and Option. The number pad is a separate switch, since most laptops do not have one. The map is a picture of a layout, not a claim about yours, so a laptop that is missing the navigation cluster simply leaves those caps dark. What matters is the code printed beside each press: that is what your keyboard genuinely sent, whatever the drawing shows.

How do I tell whether a key is actually dead?

Press every key once. Anything still dark, and still listed under Not yet pressed, did not report. Before calling it dead, check two things: that the key is not one of the firmware keys above, and that it is not being swallowed by a combination the browser reserves. If an ordinary letter or modifier stays dark while its neighbours light, the switch, the cable or the controller is the problem. Copy log gives you the recent run as plain text with timings, the last 400 events of it, which is the useful thing to attach to a warranty claim.

What is the repeat rate, and how is it measured?

Hold a key down and the operating system waits, then starts repeating it. The wait is the repeat delay and the speed afterwards is the repeat rate, and they are set separately in your system settings. This tool measures only the gaps between repeats, never the first gap, because that one includes the delay and would halve the answer. It reports the median of the recent gaps, so a single dropped frame does not distort the figure.

Why does it show KeyQ when I pressed A?

Because the two are different questions. Every event carries a code, which is the physical position on the board, and a key, which is the character your software layout produced there. On an AZERTY keyboard the position labelled A is the one a US layout calls Q, so the code reads KeyQ and the key reads a. Position is what a hardware test needs, so that is what the map marks. Both values appear in the Last key row, and the log records both.