Every key you press carries a timestamp accurate to sub-millisecond precision.
The gap between each keystroke forms a rhythm fingerprint — stable across sessions,
impossible to consciously control, and specific enough to identify you.
Your keystroke timing pattern is stable across sessions.
Researchers identify individuals from typing rhythm alone with over 95% accuracy —
without reading a single character you typed. Banks and enterprise software already
use this for continuous authentication.
0keystrokes
—avg delay ms
—rhythm hash
inter-key delay ms
min:—ms
max:—ms
type 10+ keys to generate your rhythm fingerprint
rhythm fingerprint—
▶ how keystroke dynamics biometrics work
Keystroke dynamics (also called typing rhythm or typing biometrics) is the study of how people type — specifically the timing between keystrokes. Two measurements matter most:
Dwell time — how long a key is held down before release
Flight time — the gap between releasing one key and pressing the next
These form a pattern that is as individual as a signature. Your motor memory, finger length, and learned habits combine to create timing patterns you cannot consciously alter.
Continuous authentication systems use this to verify identity throughout a session — not just at login. If someone else sits down at your keyboard mid-session, the typing rhythm shifts and the system flags it.
Keystroke dynamics require no special hardware — just the timestamps your browser already provides via KeyboardEvent.timeStamp, accessible to any webpage, with no permission required.