How to detect Caps Lock
document.addEventListener('keydown', (event) => {
if (event.key === "CapsLock") {
// Caps Lock was pressed
}
});Use event.key to react to what the key means (it follows the keyboard layout) and event.code for its physical position, for example WASD in games. keyCode and which are deprecated: they still work, but their values differ between browsers and layouts.
How browsers treat Caps Lock
To warn users that Caps Lock is on in a password field, check event.getModifierState("CapsLock") on any key event — it reports the lock state, not just this key.
In React
<input onKeyDown={(e) => { if (e.key === "CapsLock") { /* … */ } }} />JavaScript Keycode FinderPress any key and instantly see every property of the keyboard event, with a copy-ready keydown snippet for shortcuts.
Open the tool Frequently asked questions
What is the keyCode for Caps Lock?
20. It’s deprecated, though: use event.key (“CapsLock”) or event.code (CapsLock) in new code.
What is the difference between event.key and event.code?
event.key is the character or action the key produces with the current layout; event.code is the physical key position, the same on every layout.
Should I use keydown or keypress?
keydown. The keypress event is deprecated and doesn’t fire for keys that don’t produce characters, such as Escape or the arrow keys.