Reaction Time Test

FREEUtilities

TOOLReaction Time Test

Measured with performance.now() from the moment the panel turns green to your pointer-down event. Display refresh (60 Hz adds up to ~16 ms), Bluetooth mice and touchscreens all add latency, so compare runs on the same device. Tiers are WOWHOW’s own bands, not population percentiles. Warming up for 19 November? Do five runs, keep the best.

100% freeNo signupRuns in your browser

TL;DR

Tap when the panel turns green. Five rounds, random 1.5–4.5 s delay, early taps do not count.
Results: average, best, slowest and consistency (standard deviation), plus a tier from Lightning (<180 ms) to Sleepy (330+ ms).
Measured with performance.now() from colour change to pointer-down; displays and Bluetooth peripherals add a few milliseconds.
Share a 1200×630 score card. Your personal best stays on your device only.

About Reaction Time Test

A reaction time test measures the delay between a visual stimulus and your response. It is the simplest benchmark of alertness there is — coffee, sleep, age and the device you use all show up in the number. This version keeps the classic red-to-green format, adds consistency and tiers, and produces a card you can post when you beat your friends.

How It Works

Each round starts on a tap. The panel turns red and a timer waits a random 1.5 to 4.5 seconds, then flips the panel to green and stores performance.now(). Your next pointer-down event stores a second timestamp; the difference, rounded to whole milliseconds, is the round result. Tapping while red cancels the timer and restarts the round without recording a time.

After five valid rounds the tool computes the mean (your score), the minimum and maximum, and the sample standard deviation as a consistency figure. The mean is mapped to one of five WOWHOW bands. The personal best is kept in localStorage so returning visitors can see whether they improved.

Who Is This For

A gamer warming up before a ranked session and checking their reflexes are in their usual band.

Comparing morning vs late-night reaction time to see how much sleep debt costs.

A parent and teenager settling who really has faster reflexes, with a card as proof.

A UX researcher using a known-good stimulus-response baseline before testing an interface.

Scope note: Browser tests include display, input and event-loop latency; absolute numbers are 10–50 ms slower than laboratory equipment. Five rounds is enough for a fun comparison, not a clinical measurement. Tiers are WOWHOW’s own bands, not population percentiles.

How to Use

Tap the big panel (or press Space) to start a round.

Wait while it is red. When it turns green, tap immediately.

Repeat for five rounds — tapping early shows a warning and restarts that round.

Read your average, tier and consistency, then share the card or try again.

Frequently Asked Questions

On screen-based tests most adults land between roughly 200 and 300 milliseconds; Human Benchmark’s widely cited median is around 273 ms. Under 200 ms is fast, under 180 ms is rare, and competitive gamers often train into that range. This tool labels bands as Lightning (<180), Fast (180–219), Average (220–269), Relaxed (270–329) and Sleepy (330+).

Touchscreens, 60 Hz displays and wireless input all add latency between the colour change and the moment your tap is registered — often 20–50 ms combined. Compare runs on the same device, and use a wired mouse on a high-refresh monitor for your best numbers.

When the panel turns green the tool records a high-resolution timestamp with performance.now(). Your pointer-down (or key-down) event records a second timestamp; the difference is the round time. The delay before green is random between 1.5 and 4.5 seconds so it cannot be anticipated.

No. Rounds are kept in memory and your personal best is stored only in your browser’s localStorage. The share card image is generated locally.