Tukuk-OS⌨️ Keyboard Test
ℹ️ What this tool does & how it works
The browser reports three useful things per keystroke: event.key (what was typed, layout-aware), event.code (which physical switch went down, layout-blind — KeyA is the same key on AZERTY and QWERTY), and the repeat flag, which tells held keys from machine-gun chattering switches. A failing keyboard usually fails in exactly one of these streams: a dead switch sends nothing, a chattering switch sends repeated keydowns without keyup, and a stuck key shows as a code that never leaves the pressed set.
What the test can and cannot catch
A browser test sees the key events your operating system delivers, which is enough to find dead switches, stuck keys and double-triggering (a chattering contact fires keydown twice before keyup — watch the held list). It cannot test keys the OS grabs before the page sees them (Fn combos, system media keys, some firmware macros), and laptop Fn layers usually remap underneath, which is why code is the layout-blind half of the report. For a serious used-laptop inspection, press every chip here, then also open a text editor and type the whole home row — belt and braces.