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Device diagnostics · browser-local

Keyboard tester and key checker

Test physical keyboard events, held keys, simultaneous-key observations, repeats, codes, locations, fullscreen behavior, and export a local event log.

Work happens in the current browser. The route does not require an account or a server-side processing job.

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Interactive browser workspace

Keyboard tester and key checker

The live tool is loaded in this browser only. This route does not need camera, microphone, or screen-capture permission for its main task.

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What it does

Useful, focused capabilities

  • KeyboardEvent.code physical-key view
  • Held and previously tested states
  • Simultaneous-key observation
  • Repeat and location diagnostics
  • Optional local CSV export

Browser compatibility

Requirements and honest fallbacks

JavaScript; a physical keyboard and trusted KeyboardEvent support for meaningful results.

  • JavaScript
  • physical keyboard
  • trusted KeyboardEvent support
  • Fullscreen API
  • download support

Questions people ask

Clear answers and limits

Does this page capture everything I type?

Only trusted events while the test panel is focused are shown. The implementation does not transmit or automatically persist the log.

Why do some system shortcuts not appear?

The operating system or browser reserves them before the page receives an event.

Can this prove NKRO?

It can show combinations observed by this browser, but it cannot certify keyboard matrix behavior independently of the full hardware and software stack.

What is KeyboardEvent.code?

It identifies a physical key position such as KeyA or Digit1, while event.key describes the interpreted character or action.

Why is the visual layout ANSI?

It is a compact reference. Unmapped codes are still logged even when the user's physical layout differs.

What this tool checks

Test a physical keyboard by observing trusted key events while the test panel is focused. The page shows physical codes, interpreted keys, held states, repeats, locations, simultaneous presses, and an optional local event-log export. Browser and operating-system shortcuts may never reach the page, and the compact visual layout is not a complete keyboard map. The log is not transmitted or automatically persisted. Results describe events received by this browser; they do not certify NKRO, switches, firmware, or keyboard quality.

What to choose and what you get

What to choose

  • trusted keyboard events from a focused physical keyboard

Result

  • an on-page keyboard event display and downloadable event log as CSV

Supported use

  • Physical-key code, interpreted-key, repeat, location, and simultaneous-event observations.
  • Optional fullscreen testing and local CSV event-log export.

Before you start

  • System-reserved shortcuts and keys not delivered to the page cannot be observed.

Supported formats

  • Accepted formats: keyboard, pointer, timing, browser state.
  • Output formats: HTML report, CSV.

Browser support and permissions

  • Modern browser with JavaScript; timing, scheduling, clipboard, and device behavior vary by browser.
  • No camera, microphone, or screen permission is needed.

Choose the right settings

  • Choose this route to inspect key delivery, codes, repeats, and simultaneous presses.
  • Use /typing-speed-test for timed text entry and WPM.
  • Use /cps-test for click or Spacebar rate rather than key-event diagnostics.

Worked example

A physical keyboard may have a repeating key and needs its code, location, repeat and simultaneous-held states observed.

Starting facts

  • Only trusted events reaching the focused browser are visible.
  • Operating-system and browser shortcuts may intercept keys.

Observed operation: Focus the tester, press the suspect combinations and review the local event log and currently held-key state.

Review the result: Repeat the test in the intended application and device environment before concluding that hardware is faulty.

Boundary: The page cannot certify keyboard hardware, firmware, ghosting limits or events captured before the browser receives them.

Choose another tool when

  • The page cannot certify keyboard matrix behavior, NKRO, switch quality, or firmware correctness.

If it does not work

  • The operating system or browser can consume shortcuts before a KeyboardEvent reaches the page.
  • Untrusted synthetic events are not treated as physical-key observations.
  • A different physical layout can make the compact visual reference look incomplete.

Things to know

  • Observed keys depend on focus, browser event delivery, operating-system reservations, and the physical layout.

Privacy boundary

Browser interaction and local results stay in the current browser session and are not sent to an Aftermath processing service. How local processing is verified.

What this tool verifies

Reports trusted keyboard events, physical codes, locations, repeats, held states, and optional local event-log data.

Check before sharing

The event log describes what this browser received; it cannot certify the complete keyboard matrix, firmware, or operating-system path.

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