GAME TOOL / 10
Reaction Challenge
The pad waits, then turns green at a random moment — click, tap or hit space the instant it changes. Five valid rounds give your average and fastest time in milliseconds. Everything stays in your browser.
Click to start
Click the instant it turns green — 5 rounds. Tapping or the spacebar works too.
Your results
New device record!
What this challenge 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 keep 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 it works
After you start, the pad waits a random 1.5–4 seconds, then flips color on a single frame. Timing starts on that exact frame — not when the timer was scheduled — and stops on your click, tap or spacebar press, measured with the browser's high-resolution clock. Clicking before the change is a false start and replays the round; switching tabs mid-round cancels it.
The score includes your display's refresh and your input device's latency, so treat it as a personal benchmark: same device, same conditions, track whether your average drops with practice.
What is a good score?
- Under 180ms — extremely fast, pro-player territory.
- 180–230ms — fast, quicker than most people on the same device.
- 230–300ms — normal everyday reaction.
- 300ms+ — slow round; refresh rate, wireless gear and background load all add milliseconds.
Frequently asked questions
How is the millisecond number measured?
Timing starts on the exact frame the pad changes color and ends on your click, tap or keypress, using the browser's high-resolution clock. It includes display and input latency — great for tracking yourself, not a lab-grade measurement.
What happens if I press too early?
That's a false start: the round doesn't count and you replay the same round. Your summary appears only after five valid attempts.
Does it work on phones?
Yes. Screen tap, mouse click and spacebar are equivalent; one press settles once and auto-repeated keys from a held spacebar are ignored.
What if I switch away mid-round?
The in-flight round is cancelled — you can't see the change from another tab, so the timing would be meaningless. Come back and click to redo that round.
Where are results and records stored?
Only in this device's browser: your best five-round average stays local and can be cleared with one tap. Nothing is uploaded — no accounts, no global leaderboard.
What's a fast score?
Most people land at 200–300ms; practiced players hold under 200ms. Refresh rate, wireless peripherals and background load all add to the reading, so same-device comparisons mean the most.