Why do I need to lock the keyboard to clean it?
Wiping a laptop keyboard with a damp cloth presses dozens of keys at once. Without a lock you trigger system shortcuts (Cmd+Q closes apps, Alt+F4 closes windows, Win+L locks the screen, Cmd+W closes tabs), and any open document will fill with garbage characters. On macOS you can hit Cmd+Option+Power and reboot. The lock here captures every keydown event and calls preventDefault() so the browser swallows them. It is the cleanest way to wipe sticky keys without consequence.
What about the OS-level shortcuts the browser cannot block?
Some shortcuts (Cmd+Tab on macOS, Win+L on Windows, Ctrl+Alt+Del on Windows, hardware function keys, fingerprint sensors, and most accessibility hotkeys) are handled by the OS before the browser sees them — no web page can stop them. For a deeper clean, use the OS-level option: macOS has a built-in 'Clean Keyboard' mode in some versions (Touch Bar Macs); Windows has 'Filter Keys' in Accessibility. The 60-second browser lock blocks 95% of accidental triggers, which is usually enough for a quick wipe.
How do I clean a laptop keyboard properly?
Power down or at least put the laptop to sleep, then unplug it. Use a microfibre cloth lightly dampened with isopropyl alcohol (70% concentration) — never spray directly onto the keyboard. Wipe in one direction across the keys; do not let liquid drip between keys. For dust, a soft brush or a can of compressed air held upright at a 75° angle works well. Avoid bleach, ammonia, hydrogen peroxide, and acetone — all damage keycap legends and the chassis finish over time.
Why is the keypress counter showing presses if they are blocked?
The counter records every key the browser detected — those keys did NOT do anything in your other apps, because the lock calls preventDefault() on the event. The counter just confirms the lock is working: a successful wipe usually shows 20–80 blocked presses depending on how hard you press and how big your cloth is. A score of zero means you are wiping too lightly to dislodge debris (or the page lost focus — make sure you clicked into the page first).
What if I need to abort early?
Click the 'Unlock now' button — clicks still pass through, only keys are blocked. You can also alt-tab away (on macOS Cmd+Tab) since OS-level focus switches are not blockable by the browser. The lock auto-expires after 60 seconds (or whatever you set), and a soft sine chime confirms it has released. If the tab becomes inactive the lock effectively releases anyway — keys only fire on the focused tab.
Will this work on my mechanical keyboard / external keyboard?
Yes — keydown events come from any keyboard the browser sees, including USB and Bluetooth external keyboards. Some gaming keyboards with onboard macros may still fire macro outputs that bypass the OS keyboard stack and show up as raw HID data, which the browser may not catch. For a paranoid lock on a gaming keyboard, unplug it before wiping. The lock here is intended for laptop built-in keyboards, where there is no easy way to physically disconnect.