A panel turns green at a moment you cannot predict. The time between that and your tap is your reaction time, measured in milliseconds. Five rounds, one average, and a number you can actually compare against yourself tomorrow.
Take the test — freeNo sign-up, no email, no password. Open it and start.
Your best average is saved in your own browser and never leaves it.
The delay changes every round, so you cannot learn the rhythm and cheat it.
| Exceptional | under 180 ms |
| Fast | 180 – 215 ms |
| Above average | 215 – 250 ms |
| Typical | 250 – 300 ms |
| Slower than most | over 300 ms |
Simple visual reaction time for a healthy adult tends to sit near a quarter of a second. A good chunk of that is fixed biology: light has to reach the retina, the signal has to travel to the visual cortex, and the motor command has to come back down your arm. Practice sharpens the edges but never removes the floor.
Touchscreens sample your finger on a cycle and displays refresh on a cycle, and both add delay before the software ever sees your tap. A result on a phone is routinely 30 to 60 milliseconds slower than the same person on a wired desktop with a mouse. That is why the only comparison worth making is against yourself on the same device — not against a number someone quoted from a different setup.
Reflex is for curiosity and entertainment. It is not a medical device, not a diagnostic tool, and not an assessment of fitness to drive or operate anything. A slow result on a given day means you are tired, or your screen is slow, and nothing more than that. If you have a genuine concern about your reaction times or coordination, speak to a doctor rather than a web page.
Reflex is an independent hobby project. It is free, carries no advertising inside the test, and collects no personal data. Questions: hello@kloudpeak.com.