Read �key� and �code� together
Key is the interpreted character or action after your layout and modifiers are applied. Code identifies a physical key position when the browser provides one. For example, the same position can report a different character on QWERTY and AZERTY layouts. A mismatch alone does not mean the key is defective.
Find a suspect key by comparison
- Press each letter and number once, releasing between presses. Tested key codes remain listed so you can compare them with your own keyboard.
- Check left and right Shift, Control and Alt separately. Watch the modifier flags while holding a modifier and pressing a letter. Browser or OS shortcuts may intercept some combinations.
- Release everything. Held keys should return to none while the box remains focused. If a code stays held, refocus and retest that key. Losing focus can hide keyup events, so the tool clears held state on blur.
- Hold a letter briefly. Repeat events are normal OS auto-repeat, not proof of a double-firing switch. To investigate unwanted duplicates, compare slow taps in a plain text editor.
Unresponsive versus untested
The reference list covers common letters, digits, modifiers and navigation keys; it is not a required keyboard layout. A code that has not arrived may be untested, intercepted or absent from your device. Fn, media buttons, firmware shortcuts, IME composition and virtual keyboards may not produce ordinary key events.
If one key repeatedly fails in multiple apps, check the keyboard's connection and layout settings, then compare another keyboard. Follow the device's cleaning instructions rather than removing unfamiliar keycaps. Persistent failures after liquid exposure or visible damage may need repair.
Use the mouse test to check an external input setup. For a phone's on-screen keyboard, use the touch coverage test instead. Live key values stay on this page; the saved result contains counts and your assessment, not typed text.