Keystrokes

A keystroke is the act of pressing a key on a keyboard. In computing, it can refer to the physical action or the signal generated by the keyboard hardware as a key is pressed, released, or held. Applications respond to keystrokes by generating characters or triggering commands.

When a key is pressed, hardware returns a scancode; the system translates it into a keycode and maps it to a character using the active keyboard layout and the current input method. Software typically receives events such as keydown (or keypress) and keyup. Some platforms distinguish between keypress and keydown; others treat them similarly. On-screen or soft keyboards emulate keystrokes for touch interfaces.

Keystrokes enable text input, keyboard shortcuts, and game controls. Typing speed is often measured in words per minute, while keystrokes per minute is another metric used in some contexts. Keyboard layouts (for example QWERTY, AZERTY) arrange keys to optimize language use and ergonomics.

Keystroke logging records keystrokes and can be used for diagnostics and user authentication, but it also poses privacy and security risks when used without consent. Security measures include limiting access to keyboard input data and using encryption.

Accessibility features, such as sticky keys and alternative input devices, improve typing access for users with mobility impairments. Keystroke dynamics, the timing patterns of keystrokes, are studied as a biometric authentication method, while developers may implement features like input method editors and programmable keys for customization.