Reaction Time Test

What This Test Measures

This test captures the time between a visual signal (the screen turning green) and your physical response (clicking). It measures your simple reaction time, which reflects how quickly your brain processes a stimulus and sends a motor command to your hand.

The timer starts the instant the color changes and stops when you click. The result is displayed in milliseconds, giving you a precise snapshot of your responsiveness at that moment.

How the Test Works

Click once to arm the test. After a random delay (to prevent anticipation), the box turns green. Click immediately when you see green. The measurement captures pure reaction, not prediction. If you click before green appears, you get a "Too early" warning and need to retry.

Each attempt is independent. Your best score is saved in your browser so you can compare across sessions. The random delay varies between 2 and 5 seconds to keep you alert.

What Is a Good Reaction Time?

• Under 200 ms: Excellent. You're faster than most people.
• 200-250 ms: Above average. This is where trained gamers often land.
• 250-300 ms: Average for most healthy adults.
• 300-350 ms: Slightly slower, possibly due to fatigue or device latency.
• Above 350 ms: Consider factors like tiredness, screen lag, or distractions.

Factors That Affect Your Score

Your reaction time varies throughout the day based on several factors:

• Sleep: Well-rested people react faster. Even mild sleep deprivation adds milliseconds.
• Alertness: Caffeine can slightly improve reaction time; alcohol slows it down.
• Age: Reaction time typically peaks in your 20s and gradually slows with age.
• Device: Screen refresh rate, touch responsiveness, and input lag all add to measured time.
• Practice: Warming up with a few attempts often improves subsequent scores.

Reaction Time in Gaming, Driving, and Sports

Fast reactions matter in competitive gaming where milliseconds decide outcomes. Esports players train specifically to maintain reaction times in the 150-180 ms range. Drivers need quick reactions to handle sudden hazards, though actual braking involves more complex decision-making. Athletes in sports like tennis, boxing, and martial arts rely on trained reflexes that become almost automatic.

This test gives you a baseline measurement. For sport-specific performance, practice in context matters more than raw reaction time.

How to Improve Your Reaction Time

• Get consistent, quality sleep.
• Warm up with a few practice clicks before going for your best.
• Minimize distractions and close other tabs.
• Keep your clicking finger ready but relaxed.
• Practice regularly to track improvement over time.

Privacy and Accuracy

All timing happens locally in your browser using JavaScript's performance API. Your scores are never sent to a server. The best score is stored in your browser's localStorage, so clearing browser data will reset it.

Browser-based tests have limitations compared to lab equipment with specialized sensors. Device latency, screen response time, and browser throttling can add a few milliseconds to your measured time. For consistent comparisons, use the same device and browser.