Why is event.keyCode deprecated?

The W3C DOM Level 3 Events specification deprecated keyCode because its numerical values vary across operating systems, browsers, and non-US keyboard layouts. Modern standards replace it with event.key (for printable characters) and event.code (for physical key position).

What is the difference between event.key and event.code?

event.key returns the character resulting from the keypress, considering layout and Shift/Alt modifiers (e.g. "a" vs "A"). event.code represents the physical hardware key on the keyboard regardless of layout (e.g. "KeyA" on QWERTY and AZERTY).

Are any keystrokes logged or transmitted?

No. All keyboard event inspection is strictly client-side within browser memory. No data is logged, persisted, or sent across any network.

Keyboard KeyCode Tester | Real-Time JavaScript event.key & event.code Inspector