Inspect keyboard input, connect a device over WebHID, and verify rollover, modifiers and shortcut behavior in real time.
| KEY | CODE | PRESSES | RELEASES | REPEATS | LONGEST HOLD | LAST USED |
|---|
All keyboard event analysis and WebHID report handling run strictly inside your web browser. No key names, codes, device data or timing values are uploaded to a remote server.
Understand how HID keyboards deliver input to your browser, what WebHID adds, and how to read rollover and event data.
A keyboard is a Human Interface Device (HID). Its firmware sends fixed-size report packets over USB or Bluetooth; the OS decodes each report into key-down, key-up and modifier state, then the browser exposes those as keydown and keyup DOM events.
This tester watches that final browser-visible stream by default, and optionally taps the raw WebHID report stream directly when you connect a device.
Universal, layout-aware events (event.key, event.code) processed by the OS. Work in every browser on this page.
Direct device packets via navigator.hid (Chromium, HTTPS only). Proves the hardware is transmitting and surfaces VID/PID identity.
Baseline for membranes and office boards.
Hold chords of increasing size — pills light up as each tier is observed.
It verifies that every key on your Human Interface Device (HID) keyboard registers correctly. This tool inspects the keyboard input stream your browser receives — key presses, releases, auto-repeats, modifiers and simultaneous chords — so you can spot dead, stuck or ghosting keys.
WebHID is a browser API that lets a web page open a direct connection to a HID device such as a gaming keyboard. It is available in Chromium-based browsers (Chrome, Edge, Opera) over HTTPS. Firefox and Safari do not support navigator.hid yet — the tester still works there using normal browser keyboard events.
No. The tester works out of the box using standard DOM keyboard events. Connecting via WebHID is optional: it surfaces the raw HID input reports stream in addition to key events, and displays device name, Vendor ID and Product ID.
Key events are processed, OS-level translations of your typing (with layout and modifiers applied). HID reports are raw byte packets the keyboard firmware sends over USB or Bluetooth. WebHID reports prove the keyboard hardware itself is transmitting, even when the OS filters the keystroke.
Rollover is how many keys a keyboard can report simultaneously. 2KRO handles two keys, 6KRO six, and NKRO (N-Key Rollover) any number. The rollover tier pills light up as your maximum simultaneous key count reaches each level.
Operating-system and browser reserved shortcuts (Ctrl+T, Alt+Tab, Cmd+W, media keys) are consumed before the page sees them. Nothing on a web page can intercept those, so use the key-event log for the keys the browser can actually observe.
Capture Mode calls preventDefault() on keys that normally scroll or move focus (Space, Tab, Arrows) so the test session is not interrupted by browser navigation. It cannot block OS-level hotkeys.
No. All event capture, WebHID report handling, filtering and statistics run entirely in client-side JavaScript inside your browser. Nothing you type is uploaded, stored or transmitted.
