Free Online Tool

Latency & Reaction Time Test

Measure how fast your brain and body respond to visual stimuli. Test your reaction time across multiple attempts, track your average, and find out where you rank.

100% Free · No Sign-Up · Mouse & Touch · Instant Results
Avg (ms)
—
Best (ms)
—
Worst (ms)
—
Attempts
0 / 5
Consistency
—
Reaction time per attempt (ms) Run attempts to see your chart
Attempts:
5
Average Reaction Time
—
milliseconds
Best
—
milliseconds
Worst
—
milliseconds
Std Dev
—
consistency spread
Consistency
—
score
False Starts
0
clicked too soon
Total Time
—
seconds
Your Performance
—
Complete the test to see your rating.
What You're Measuring

Reaction Time vs Latency — What's the Difference?

Reaction time is the total delay from a stimulus appearing on screen to your physical response registering. It combines two things: your brain's biological processing speed and the hardware latency of your entire input chain — monitor, mouse, USB polling, and OS event handling.

This test measures end-to-end latency as you experience it in real life. It can't isolate pure biological reaction time from hardware delay, but it gives you an honest, practical number — the same one that determines whether your shot registers before your opponent's in a competitive game.

Biological Latency
Your brain needs 100–150ms just to process a visual signal and send a motor response. This is your hard biological floor.
Monitor Latency
Every display adds input lag — from 1ms on a 240Hz gaming monitor to 30ms+ on budget panels. This adds directly to your score.
Mouse & USB Polling
A 125Hz mouse adds up to 8ms per poll. A 1000Hz gaming mouse adds less than 1ms. Polling rate is the easiest hardware upgrade for lower latency.
Fatigue & Focus
Reaction time worsens with sleep deprivation, dehydration, and mental fatigue — by 20–50ms. Your best scores come when you're alert and warmed up.
The Full Chain

Where Your Latency Comes From

Every click you make in a game or test passes through this chain. Each step adds delay. Understanding where the milliseconds come from helps you know what's worth optimising.

01
Screen Renders
Monitor displays the stimulus. Panel lag adds 1–30ms depending on technology and refresh rate.
02
Eye Receives Light
Photoreceptors convert light to nerve signals. Takes roughly 20–40ms to fire reliably.
03
Brain Processes
Visual cortex decodes the signal and decides on a response. Accounts for 80–120ms of total delay.
04
Finger Moves
Motor neurons fire and your finger physically depresses the button. Adds roughly 30–60ms.
05
Mouse Registers
Mouse polling interval (1–8ms) and switch debounce (1–5ms) determine when the click is detected.
06
OS & Browser
The OS interrupt handler and browser event loop deliver the click to the test. Adds 1–5ms typically.
Benchmarks

What's a Good Reaction Time?

Human reaction time varies with age, fitness, and gaming experience. Here's how different scores compare across the general population:

Avg Reaction TimeRatingWho's HereNotes
Below 150msSuperhumanStatistically rare — possible with specific hardwareLikely hardware-influenced result
150 – 200msElitePro esports players, trained athletesTop 1% of the population
200 – 250msFastRegular gamers, athletesTop 10–15%
250 – 300msAverageTypical healthy adultsPopulation median is ~270ms
300 – 400msSlowNon-gamers, older adults, fatiguedNormal — most people land here
400ms+Very SlowTired, distracted, or first attemptWarm up and retry
How to Improve

Reduce Your Reaction Time

  • 01
    Upgrade to a High-Refresh Monitor
    Moving from 60Hz to 144Hz reduces motion blur and frame delivery lag by 10–15ms. At 240Hz the improvement is even more dramatic — frames arrive every 4.2ms instead of 16.7ms, making the image feel far more immediate.
  • 02
    Use a 1000Hz Mouse
    A mouse polling at 125Hz can add up to 8ms of input lag per poll. A gaming mouse at 1000Hz reduces that ceiling to under 1ms. This is the cheapest and most measurable single hardware upgrade for lower latency.
  • 03
    Warm Up Before Testing
    Your first 3–5 attempts are always slower — your brain needs to calibrate to the task. Reaction time improves 20–50ms after a short warm-up. Always discard your first few scores when benchmarking.
  • 04
    Sleep and Hydration
    Sleep deprivation of even one hour measurably slows reaction time by 20–40ms. Dehydration adds another 10–20ms. Your biological ceiling can only be reached when your body is properly rested and fuelled.
  • 05
    Enable Game Mode on Your Monitor
    Most monitors have a "Game Mode" or "Low Input Lag" setting that disables post-processing (sharpening, dynamic contrast, motion smoothing) and cuts display latency by 5–20ms. It's free and takes 30 seconds to enable.
  • 06
    Use a Wired Connection
    Wireless mice and keyboards add variable latency. Even the best wireless gaming mice have 1–2ms more lag than their wired equivalents in burst scenarios — and cheaper wireless peripherals can add 10–30ms unpredictably.
FAQ

Questions, Answered

That's completely normal. Biological reaction time varies naturally by 20–50ms per attempt depending on your level of focus, anticipation, and muscle readiness. The standard deviation shown after your test tells you how consistent you are — a lower number means more reliable reactions.
Not directly — but your monitor's input lag is baked into your result. This test measures the total end-to-end latency including your display, your brain, and your input device. If you're curious about your monitor's isolated input lag, dedicated hardware tools like a Leo Bodnar tester are the proper way to measure that independently.
A false start happens when you click before the green signal appears — you were anticipating rather than reacting. It doesn't count toward your average and is tracked separately. Too many false starts means you're timing the delay rather than genuinely reacting, which inflates your performance artificially.
At least 5 attempts gives a reasonable average — this is the default. For a statistically reliable result, 10–15 attempts is better. With more attempts the standard deviation stabilises and outliers (blinks, distractions) have less impact on your average. Professional reaction tests use 20–30 trials.
In games, "reaction time" often refers to a specific mechanical action like flicking to a target — not a simple click test. Game engines also predict inputs and pre-render frames. Additionally, some gamers are measuring in-game performance which includes game-side prediction. A browser-based visual reaction test like this one captures pure end-to-end latency more honestly.
Yes, modestly — studies consistently show caffeine improves reaction time by 10–30ms at moderate doses (100–200mg, roughly one coffee). The effect is stronger when you're tired or sleep-deprived. It has less impact when you're already alert and well-rested. The more important variables are sleep quality, hydration, and being genuinely focused during the test.
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