Online Reaction Time Test
Test your reaction time online for free, right in your browser. No app to install, no account to create. SERO runs ten precision rounds in about 90 seconds and reports your exact reaction time in milliseconds. Compare your score against the global average and find out where you sit on the international leaderboard.
▶ Start the test nowFree · 90 seconds · No signup
How the online test works
Ten short levels, one tap each. You watch a timer race down and stop it as close to 0.000 seconds as you can. The closer you land, the higher you score. Every input is captured at frame-level precision — about ±3 ms on a 144 Hz screen, ±8 ms on a 60 Hz phone.
What counts as a good result
Average adults react at around 250 ms to a visual cue. Below 200 ms is fast, below 170 ms is gamer-tier, below 150 ms is elite. SERO measures precision, not just raw reaction, so a strong score here is harder to fake than a simple click-on-green test.
Why people use SERO instead of older tests
Most online reaction tests have one screen, one click, no leaderboard. SERO has ten levels, a real-time global ranking, a 14-day competitive season and a free Android app on Google Play. The result feels like a game, not a lab experiment.
Frequently Asked
Is the online reaction time test really free?
Yes — no signup, no payment. Optional cosmetic skins exist but never affect your score.
How accurate is an online reaction test?
On a 144 Hz display SERO measures within ±3 ms. On 60 Hz it is ±8 ms. That is more than precise enough for ranking purposes.
Can I improve my reaction time with daily testing?
Yes. Most players gain 10–20 ms within two weeks of 5-minute daily practice.