cursor tremor biometric

even when you try to hold your hand completely still, your muscles produce tiny rhythmic contractions called physiological tremor — typically 8–12 hz in healthy adults. this tremor is encoded in your cursor micro-movements. it's biometric: stable, personal, and completely unaffected by changing mouse hardware, browsers, or user accounts. park your cursor in the target zone below and hold as still as you can for 20 seconds.

✦ wrist resting on desk · mouse barely held · hand still · no intentional movement

• survives everything. changing mouse, changing browser, clearing cookies, using incognito, using a vpn — none of it changes your tremor frequency. it's generated by your spinal cord and cerebellum, not your hardware. the only way to change it is neurological medication or disease progression.
• medical classification. parkinson's tremor peaks at 4–6 hz (rest tremor), essential tremor at 10–15 hz (action tremor), cerebellar ataxia at 3–5 hz (intentional tremor). neurologists use these signatures for differential diagnosis. a browser can measure the same signal.
• continuous identification. unlike a password, which you enter once, tremor fingerprinting works passively throughout a session. as long as the cursor moves, the biometric is being refreshed. financial platforms have patented this for fraud detection.
• pointer events expose sub-frame resolution. high-polling-rate mice (1000 hz) can be read at full rate via getCoalescedEvents(). even at 60 fps, the frequency content up to 30 hz — well above the tremor range — is accessible.