What is a normal human reaction time?

For a simple visual stimulus and a mouse click, most healthy adults have reaction times between 200 and 250 milliseconds. Times below 180 ms are considered very fast, while times above 300 ms are slower than average.

How does this reaction time test work?

The test shows a panel that changes from a waiting state to a GO signal after a random delay. As soon as you see the GO signal, you click or tap. The tool measures the time between the visual change and your response, in milliseconds, and repeats this for several trials to compute your average and best reaction time.

Can I improve my reaction time?

Reaction time is influenced by age, sleep, caffeine, distractions, and training. You can improve it modestly with practice, good sleep, and by reducing distractions. However, there are biological limits, and you should not expect huge changes from one day to the next.

Why are my reaction times different on phone vs. computer?

Different devices, screens, browsers, and input methods add small delays. Touchscreens, wireless mice, and high-latency displays can all affect the measured reaction time. Use the same device and browser when comparing your own results over time.

Is this reaction time test accurate enough for medical or professional use?

No. This test is designed for personal interest, education, and training only. It is not a medical device and should not be used to diagnose conditions, assess fitness to drive, or make safety-critical decisions.

Reaction Time Test

Measure how fast you can react to a visual signal, track your average and best reaction time, and compare your results to typical human ranges.

Mode:

Click or tap to start

When the panel turns green, react as fast as you can.

Tip: You can also press the spacebar.

Trials per run:

Last

–

Average

–

ms (this run)

Best

–

ms (all runs)

Trials

0 / 5

completed

How to read your result

Complete at least 5 trials to see how your reaction time compares to typical human ranges.

Average reaction time	Interpretation
< 150 ms	Suspiciously fast – likely a device or input artifact.
150–200 ms	Extremely fast – elite gaming / e-sports level.
200–250 ms	Typical healthy young adult.
250–300 ms	Slightly slower than average, still normal.
> 300 ms	Slow – often due to fatigue, distraction, or age.

What is a reaction time test?

A reaction time test measures how long it takes you to respond to a stimulus – in this case, a visual change on the screen. The delay between the stimulus appearing and your click or tap is your reaction time, usually measured in milliseconds (ms).

How this online reaction time test works

Click or tap the panel (or press the spacebar) to arm the test.
After a random delay (typically 1–3 seconds), the panel turns green or shows a GO signal.
As soon as you see the GO signal, react as quickly as possible.
The tool records the time between the signal and your response.
Repeat for several trials to get a reliable average.

Reaction time formula
In this test we compute:

reaction_time_ms = response_timestamp −
                  stimulus_timestamp

where timestamps are recorded using performance.now() for sub‑millisecond precision in the browser.

Factors that affect reaction time

Age: Reaction times are fastest in late teens to early 30s and tend to slow gradually afterward.
Sleep & fatigue: Being tired, drowsy, or sleep‑deprived can significantly slow your responses.
Caffeine & medications: Stimulants can speed you up; sedatives and alcohol slow you down.
Practice & familiarity: Repeating the same task can improve your performance slightly.
Device & input lag: Screen refresh rate, mouse/keyboard latency, and browser performance all add small delays.

Tips for more consistent results

Use the same device and browser when comparing your own scores over time.
Close other heavy apps or browser tabs that might cause lag.
Rest your finger on the mouse button or screen, but avoid pre‑clicking.
Run at least 10–20 trials for a stable average.
Test at similar times of day if you are tracking changes over weeks or months.

About the different modes

Simple (Click when green): Classic reaction test – wait for the panel to turn green, then react.
Go / No-Go: Sometimes the panel shows a red “NO” signal. You must react only to “GO” and ignore “NO”. This tests both speed and impulse control.
Sequence (1–2–3): Three quick GO signals appear in sequence. Your average is computed across the sequence, simulating repeated reactions (e.g., gaming or sports).

Important disclaimer

This reaction time test is for personal interest, education, and training only. It is not a medical device and must not be used to diagnose any condition, assess fitness to drive, or make safety‑critical decisions. If you are concerned about your reaction speed or cognitive function, speak with a qualified healthcare professional.