Five valid rounds
The session uses five completed reactions rather than treating one lucky or distracted attempt as the whole result.
WAIT · SEE · REACT
Reaction Time Test
Check your reaction time in milliseconds with a randomized visual cue and five valid rounds.
Start a round, wait for NOW, then respond once. Your first valid response locks the session to Mouse, Pen, Touch, or Keyboard.
Round1 of 5
StateReady
InputNot locked
False starts0
Ready. Start the test, then wait for the visual cue.
SESSION RESULT
Reaction time result
0ms median
Average0
Best0
Slowest0
Valid rounds5
Round 1—
Round 2—
Round 3—
Round 4—
Round 5—
What the Reaction Time Test measures
This visual reaction time test measures the browser-observed interval between a randomized NOW cue and your first accepted response. Results are shown in milliseconds, where a smaller measured interval means a faster response under that setup.
Randomized wait
Each round waits an unpredictable 1.5 to 4.5 seconds before NOW appears so you cannot rely on a fixed countdown.
False starts
Responding before NOW cancels that attempt and does not consume one of the five valid rounds.
How the result is summarized
Primary result = median of 5 valid reaction times
The app also shows the arithmetic average, best, slowest, and every attempt in original order. Median is the middle value after sorting the five measurements and is less dominated by one unusually slow round.
Example: 200, 220, 240, 260, and 280 ms produce a 240 ms median, 240 ms average, 200 ms best, and 280 ms slowest.
Use the same input and setup for comparisons
The first valid response locks the session to Mouse, Pen, Touch, or Keyboard. Compare repeated sessions on the same device, browser, display, and input method whenever possible.
Browser timing has real limits
The app uses a monotonic high-resolution browser clock and arms the visual cue through the browser animation frame path. The measured interval still includes browser scheduling, display presentation, operating-system behavior, and input-device event delivery. It is not the exact biological delay from photons reaching your eyes to muscle movement.
This is not a clinical reflex test
Reaction Time Test is an interactive browser measurement, not a neurological reflex examination, medical diagnosis, driving-fitness assessment, monitor pixel response-time test, or server response-time test.
Private by default
Your rounds and scores stay in page memory. There is no account, leaderboard, score upload, or app-owned browser history. Copying a result happens only when you choose Copy result.
Related tests
For repeated clicking speed, use Click Speed Test. For mouse-button and wheel diagnostics, use Mouse Tester. For repeated Space-key speed, use Space Bar Click Test.
What does reaction time mean here?
It is the browser-observed time from the visual NOW cue baseline to the first accepted response event, reported in milliseconds.
Why is the wait random?
A variable delay reduces anticipation from a predictable countdown and makes each round depend on seeing the cue.
Does a false start count?
No. The false-start total increases, but the same numbered round must be tried again.
Why five rounds?
Five valid rounds provide a small session distribution so the app can show median, average, best, and slowest instead of relying on one attempt.
Can I use touch or keyboard?
Yes. The first valid response locks the whole session to one input class so unlike conditions are not mixed into one summary.
Are results saved?
No. Refreshing, closing, or leaving the page can discard the current session.
Read the testing guide for timing method, comparison limits, and false-start behavior.