Measure visual response time over repeat trials with early-start detection.
Complete up to 10 trials. Wait for the green “GO” message, then press the test area or Space/Enter while it has focus. An early response does not count.
Ready. Choose your settings and start when comfortable.
Reaction time uses performance.now() when GO is rendered and when the response is handled. Screen refresh, input latency and browser scheduling affect results. This is a practice game, not a medical or neurological measurement. Hidden tabs cancel trials; early starts never count. Up to 10 completed trials per session; Reset clears them.
Leaving the page or switching tools releases this session. No text or interaction history is stored or uploaded. Changing settings resets the result.
Start arms a trial. A random delay of 1.5–4 seconds follows. Respond only after GO appears. Pointer presses and nonrepeating Space/Enter work in the focused test area.
Your practice text and interaction results stay on your device. All scoring runs locally without accounts, uploads, analytics of your keystrokes or persisted input history.
Reaction time uses performance.now() when GO is rendered and when the response is handled. Screen refresh, input latency and browser scheduling affect results. This is a practice game, not a medical or neurological measurement. Hidden tabs cancel trials; early starts never count. Up to 10 completed trials per session; Reset clears them.
No. Typing is handled only in the labelled practice input, and click or reaction responses only in their dedicated test area. There is no global keystroke recorder or background interaction tracking.
An active session ends when this document is hidden. This avoids counting time spent away from the test. A reaction trial is cancelled without adding a result. Return and start a new session or trial.
