Reaction Time Test — Find Out How Fast You Really Are
SERO is a precise reaction time test that runs directly in your browser. No download, no signup. You stop a fast countdown timer at exactly 0.000 seconds across ten levels. Every input is captured at frame level, so the score reflects your true reflexes with just a few milliseconds of margin. Built lightweight enough to feel instant even on mid-range Indian Android phones.
▶ Start the test nowFree · 90 seconds · No signup
How the reaction time test works
One round takes about 90 seconds: ten short levels, each with its own running timer. You tap or click the exact moment the counter hits zero. The closer you land to 0.000, the higher you score. After every level the app shows your exact value in milliseconds — no rounding, no sugar-coating.
What counts as a good reaction time
The average adult visual reaction time is around 250 milliseconds. Under 200 ms is considered fast, under 170 ms is competitive gamer level, under 150 ms is elite. SERO measures precision on top of raw speed, which is why it is harder and more honest than classic "click when green" tests.
Mobile vs desktop on Indian networks
The most accurate setup is a desktop with a high-refresh display (120 Hz or more). Mobile also works great — touch events are processed instantly and the game runs fully offline once loaded, so even patchy 4G or Jio connections never affect your score. Average desktop advantage is 15–30 ms.
Global leaderboard with country ranks
Every 14 days a new season starts and the board resets. New players get a real shot at the worldwide top 100. There is also a country-specific leaderboard so you can see exactly where you stand among other Indian players. Personal bests are preserved forever in your profile.
Frequently Asked
Is this reaction time test free?
Yes, fully free. No signup required to play, no hidden cost. Optional cosmetic skins exist but never affect your score.
Does it work on Indian phones?
Yes, it runs smoothly on any Android phone or iPhone made in the last five years, using just a few MB of data after first load.
What is an average reaction time?
Around 250 ms for adults on visual reaction. Pro gamers usually sit below 200 ms.
Can I train my reaction time?
Yes. Two weeks of 5 minutes per day produces a measurable 10–20 ms improvement for most players.