Keyboard Tester: Test Every Key Online

How to test your keyboard

Pick your keyboard’s size and layout, click the picture (or Tab to it and press Enter or Space), then press every key once. Keys turn solid while held and keep a tick after release, so a key that never lights up is faulty or swallowed before it reaches the browser. Keys that are not drawn, such as media keys or F13 to F24, appear under Other keys. On Macs and many laptops the top row sends brightness and media controls; hold Fn to test F1 to F12. The Fn key itself never reaches a web page, so it is drawn dashed and not counted.

While capturing, the page blocks keys that would scroll or leave the page, such as Space, the arrows, Tab, Backspace and F1 to F12, and browser shortcuts such as Ctrl+S or Ctrl+P. Press Esc twice in a row, or click elsewhere, to stop. No page can block system shortcuts such as Alt+Tab, Cmd+Tab or Ctrl+Alt+Del, or a few browser ones such as Ctrl+W.

Layouts

Compact boards vary between brands, so a key in a different spot on yours shows up under Other keys. The drawing is lit by code, the physical key position named after the US key in that spot, so the legend choice only changes the printed labels: on a German board the key labelled Z sends KeyY, and a 60% board’s top-left key counts whether it sends Esc or the backquote.

What the numbers mean

Each press fires a keydown event and each release a keyup event, as defined in the W3C UI Events specification. key is the character or action produced (a, A, Enter), which depends on layout and Shift; code is the physical key (KeyA, NumpadEnter); keyCode is the deprecated legacy number (65, 13); location is 0 for standard keys, 1 left, 2 right and 3 numeric keypad; repeat is true for auto-repeat while a key is held. Legacy keyCode values differ between browsers for a few punctuation keys: Firefox reports 59 for semicolon, 61 for equals and 173 for minus, where Chrome and Safari report 186, 187 and 189.

Rollover and ghosting

Choose a combination under Rollover test and hold all its keys at once. Each key lights when the keyboard reports it, and the result keeps the most that registered together. A keyboard with a basic matrix may drop the third or fourth key (blocking) or report a key you did not press (ghosting), which shows as an extra held key. A USB keyboard that sends the standard 8-byte boot report stops at six non-modifier keys plus modifiers, while n-key rollover boards should pass every combination. Test the combinations you actually use, such as W, A, S and D with Shift and Space for games.

Key chatter

A worn or dirty switch can bounce and register one press as two. The tester flags possible chatter when a key goes down again within the chosen threshold (50 ms by default) of being released, faster than people repeat a key on purpose, and lists each such key with its count and shortest gap. The log’s Timing column shows how long each key was held and the gap before its next press. Compressed air sometimes cures a chattering switch; otherwise it needs replacing, and QMK and similar firmware let you raise the debounce time.