How to use this test
Activate key capture
Select the test area before pressing a key. Capture applies only while that area is active.
Press the key once
Watch for the key label, physical-code value where supplied, and modifier state shown by the page.
Try problem keys carefully
Test letters, modifiers, arrows and function keys individually. Use Escape or Stop to leave the test.
Compare with another app
If a key is absent here, try a basic local app or another browser before drawing conclusions about hardware.
What we check
While the test pad is active, the page listens for browser keyboard events and marks a visual layout when it receives keydown and keyup. It can display the key value, modifier state, repeat flag and physical-code value when the browser supplies them.
A received event shows that this browser received that input while the page had focus. It does not reveal switch condition, keyboard firmware, scan rate, or every input path used by the operating system.
The test processes events only while the test surface is active. It keeps the visual set of tested keys for the current session, but does not save or upload typed text. Escape provides a predictable way to exit capture mode, alongside Reset.
What this test can’t tell you
Browser-reserved shortcuts, operating-system hotkeys, security controls and accessibility software may intercept keys before the page can see them.
Virtual keyboards, non-standard layouts and some assistive devices can expose different or incomplete values. A missing event is not a hardware diagnosis.
Something not working?
Nothing happens when I press a key
Click or tab into the active test area, then try again. Check whether the page shows a focused state and whether another window has taken focus.
A shortcut does not appear
Browser and operating-system shortcuts may be reserved. Test an ordinary character key first, then use another local application if the shortcut matters.
The wrong character appears
Check the selected keyboard layout, language and modifier keys in the operating system. The physical-code value can differ from the character produced.
A key works sometimes
Try repeated single presses, another USB port or a wired connection, and another app. This page can show received events but cannot identify the cause of intermittent hardware behaviour.
Common questions
Does this page save what I type?
No. It uses live key events while the test is active and keeps only the visual set of tested keys for the current session. It does not save or upload typed text.
Why are key and code different?
Key describes the character or action produced under the current layout. Code, where available, identifies a physical keyboard position, so the two can differ.
Can it test laptop function keys?
Some function keys are handled by firmware or the operating system and never reach the browser. The page can only show events it receives.
Can it diagnose a broken switch?
No. It can provide a focused browser observation. A physical diagnosis needs comparison across applications and, if necessary, hardware support.