The panel turns red. Hold still, clicking now is a false start and costs you the round.
2
Wait for green
After a random delay of 1.3 to 3.5 seconds, the panel flashes green. That's your signal.
3
Click as fast as you can
The instant you see green, click. Your reaction time in milliseconds appears. The clock measures from green pixels on screen to your click, not from setTimeout to mouseup.
4
Repeat for five rounds
Each run is five rounds. False starts reset that single round; the rest of the run is unaffected.
5
Compare your average
We show your fastest, slowest, and average. Quality label: under 220ms is Excellent, around 270ms is Average, over 450ms is Slow.
Tips & strategy
•Don't anticipate. The wait is random, trying to guess the green will only cause false starts. Watch and react.
•Use a mouse, not a trackpad. Mouse buttons have less travel distance than trackpad clicks; you'll save 20–40ms.
•On mobile, tap with your thumb directly over the panel. Tapping with a different finger introduces extra travel time.
•Run it with a wired connection if you're chasing your best score. Wireless mice and Bluetooth keyboards add ~5–15ms of latency.
•Warm up. Your first one or two clicks of a session are typically 10–30ms slower than the rest. Don't trust round 1.
•Eye strain matters. If your screen is dim or you're tired, expect 30–50ms slower. Lighting helps.
Frequently asked questions
What's a normal reaction time?
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Average for humans is about 250–270ms for visual stimuli. Skilled gamers and athletes commonly hit 180–220ms. Under 150ms is exceptional, and below 100ms is impossible without cheating (the eye-to-brain pathway alone takes ~100ms).
Why is my time slower here than on humanbenchmark?
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It shouldn't be. Melio measures paint-to-press (green pixels on screen → pointerdown event), the same method humanbenchmark uses. If you see a consistent 50ms+ gap, the difference is likely your input device, display refresh rate, or browser.
Does monitor refresh rate matter?
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A bit. A 60Hz monitor adds up to 16ms of paint latency; 144Hz adds ~7ms; 240Hz adds ~4ms. The difference is real but small relative to your reaction itself.
What's the world record?
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Around 100ms for verified, repeated trials. Below that is generally considered statistically impossible given the speed of nerve signals from retina to motor cortex.
Does caffeine help?
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Moderately, yes. Studies show ~20–30ms improvement with normal caffeine doses. Alcohol slows reaction times by 30–80ms even at low blood alcohol levels.
Why do I get a false start?
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Clicking before the panel turns green counts as a fault. Your brain anticipated the green and your hand fired early. That round resets, the rest of your run is fine.