Reaction Time Test
Stay focused after starting: the pad changes color after a random 1.5–4s delay — click instantly. Five valid rounds produce your average reaction in milliseconds.
Click to start
When the pad changes color, click as fast as you can. 5 rounds — tapping or the spacebar works too.
Your results
New device record!
What this test does
- Five timed rounds measure how fast you react to a sudden color change — per-round times, your average and your fastest, all in milliseconds.
- Mouse, touchscreen and spacebar all work; a built-in cooldown and key-repeat filter stop double-clicks and held keys from corrupting a round.
- Honest scoring: click too early and the round replays instead of counting; leave the tab mid-round and the attempt is cancelled, not silently timed.
- One-tap PNG score card with the site name, date, all five rounds and your summary — sized to share from phone or desktop.
Why this tester
- Frame-accurate start: the clock starts on the exact frame the color flips on screen, not on the scheduled timer — the fair way to measure what you actually saw.
- Runs entirely in your browser: no account, no upload, no server round-trips. Your best five-round average stays on this device and you can wipe it anytime.
- Free and instant with no install — open the page and test, on phone or desktop, in Chinese or English.
How to read it
- Most adults land at 200–300ms on a phone or laptop; under 200ms is fast. The number includes your screen refresh and input latency, so compare your own runs rather than other people’s devices.
- Timing starts on the frame the pad actually changes color and ends on your key or pointer press — a real browser measurement, not lab-grade hardware precision.
- Clicking before the change is a false start: the round is discarded and retried. Switching away mid-round cancels it too.
Frequently asked questions
How accurate is the millisecond number?
It's a browser-side measurement: timing starts on the same frame the color actually appears and ends on your press, so it includes display refresh and input latency. Good for comparing yourself over time — not a lab-grade hardware measurement.
What happens if I click too early?
That's a false start: the round doesn't count and you retry the same round. The summary appears only after five valid attempts.
Can I use a phone or the keyboard?
Yes. Mouse click, screen tap and the spacebar are equivalent; a single press settles once, and repeated keys from holding the spacebar are ignored.
Where are my results stored?
Only in this device's browser: your best five-round average is kept locally, can be cleared with one tap, and is never uploaded — no accounts, no global leaderboard.
What if I switch away mid-round?
The in-flight round is cancelled — you couldn't see the color change anyway, so the timing would be meaningless. Come back and click to redo that round.