Reaction Speed Tester
Measure your response time to a visual signal over five rounds.
Five visual reaction rounds
Click the panel only after it turns green. Early clicks restart the test. This measures your device, display, and input path along with your reaction.
Tool guide
About Reaction Speed Tester
Measure responses to a visual cue across five rounds. Early clicks count as a false start, and the average combines human response with screen, browser, and input delays.
How to use this tool
- 1Start the test and wait while the panel shows the waiting state.
- 2Click only after the panel turns green; repeat for all five cues.
- 3Read the average response time and try again under similar conditions if comparing results.
How the tool works
The page records a performance timestamp when the cue changes and compares it with the click event. It averages five response times. Random wait intervals discourage guessing, while false starts cancel the run.
Worked real-world example
A 250 ms response is the time between the browser cue timestamp and click event for that round, not a direct measurement of brain processing alone.
Common scenarios and use cases
Play a quick reaction game or compare your own sessions on the same device.
Important details and limitations
This informal browser result is not a medical, attention, or driving-safety assessment. Refresh rate, event timing, fatigue, and anticipation can change results; never use it to judge safety-critical ability.
Check the output unit as well as the number. If the result will be reused in another calculation, retain full precision where possible and round only at the end. For measurements governed by a technical specification, use the standard and tolerance required by that document.
Frequently asked questions
Why does an early click fail the round?
It prevents a guessed response from being counted as reaction time.
What does the average include?
The device and browser timing path as well as your response.
Can I use it for a health diagnosis?
No. It is a casual game, not a clinical test.