Keyboard Test

Keyboard Test draws a full-size keyboard and lights each key while you hold it down. Once a key has worked it stays marked, so after a pass over the keyboard the keys left blank are the ones that did not register. Beside the picture it shows what the last key typed (its key value, such as “a” or “Enter”), which physical key it was (its code, such as KeyA or ShiftRight), whether it was the left or right copy of a key or on the number pad, which modifiers were held with it, and whether the key is auto-repeating. It also counts the most keys you have held at once, which is how you check a keyboard’s rollover: a gaming keyboard should register every key you press together, while many office and laptop keyboards stop at two to six keys and drop the rest.

1. Click the test area (or press Tab until it is highlighted) so the keys go to the test rather than to the page.
2. Press each key in turn. Keys light while held and stay marked once they have worked; blank keys have not registered.
3. To check rollover, hold several keys together — for example A, S, D, F and the space bar — and read “Most keys held at once”.
4. Press Esc and then Tab to leave the test area, or Start again to clear the marks.

• Some keys never reach a web page. The Fn key is handled inside the keyboard itself; media, volume and brightness keys go to the system; Windows or the Mac may keep combinations such as Alt+Tab, ⌘+Tab, Ctrl+Alt+Delete or the Windows key for themselves. A blank there is not a fault.
• Print Screen often reaches the page only when it is released, and some systems take it for a screenshot first; it is counted on release.
• The picture is a US-style (ANSI) full-size keyboard. On a UK or other ISO keyboard, the key beside left Shift lights as the extra backslash key; the code names the physical position, not the character printed on your key.
• Rollover depends on which keys are pressed together, because cheaper keyboards share wiring between keys. If three keys register and a fourth does not, try a different set of keys before deciding.
• On a phone or tablet, the on-screen keyboard sends few or no physical key codes; this test is for hardware keyboards.
• The key presses are read by this page in your browser and are not typed anywhere, recorded or sent. Nothing is stored: closing or reloading the page forgets every mark. That matters on a keyboard test, because you may press keys you would type a password with — no key you press here leaves the page.

Press every key once. Each key that works turns coloured and stays coloured; the keys left blank did not send anything. Press a blank key again, firmly and in the middle, before deciding it is dead — and check the limits above, because keys such as Fn never reach a web page.

The code names the physical key: KeyQ is the key left of W wherever it is, whatever language the keyboard is set to. The key is what that press types under your current layout: on a French keyboard the KeyQ key types “a”. Games use the code; text uses the key.

Rollover is how many keys a keyboard reports at once. Ghosting is when pressing some combinations makes a key that was not pressed appear, and many keyboards block extra keys to prevent it. Hold several keys together and compare the count with how many you are holding.

If the key keeps auto-repeating after you release it, the switch may be stuck. If it only stayed lit because the window lost focus while you held it, click the test area again — keys are cleared whenever the page loses focus.