Reaction Time Test
Last updated: 2026-06-25
The reaction time test measures the time from seeing a signal to clicking, in milliseconds (ms): you click the instant the screen turns green.
It runs 5 trials and shows your average and best record. Simple visual reaction time is usually 200-270ms. Scores are for-fun reference figures.
Reaction Speed Measurement
Reaction Time Test
Click the area or press the spacebar to start. (5 trials)
Average reaction time
0ms
| Trial | Reaction time |
|---|---|
| Average |
The measured value includes mouse/touch input lag and monitor/browser delay in addition to your human reaction time. Scores are for-fun reference figures.
How to use
- Start — Click the measurement area or press the spacebar to start the test.
- Wait — Wait while the screen is red. Clicking while it is red counts as invalid.
- Click — Click (or press the spacebar) as fast as you can the instant the screen turns green.
- See results — After 5 tries, your average, best record, and grade are shown in a table.
What reaction time is and how it is measured
Reaction time is the interval from the moment you detect a signal to the moment you complete the matching action. This test measures the simplest form, simple reaction time. Because the only rule is "press as soon as you see green," the judgment of distinguishing or choosing colors is kept to a minimum.
The measurement calculates the difference between the moment the screen turns green and the moment you click, in milliseconds (ms). The wait before green is randomized each time to stop you from memorizing the timing and pressing early.
| Average reaction time | Grade | Description |
|---|---|---|
| ~ 200ms | Very fast | Top-tier gamer / athlete level |
| 201 ~ 250ms | Fast | Faster than average |
| 251 ~ 300ms | Average | Typical adult average range |
| 301 ~ 400ms | A bit slow | Possible fatigue or environment effects |
| 401ms ~ | Slow | Check input lag and focus |
The grades above are simplified reference standards from general statistical ranges. They are not a precise medical assessment; for more detail see the Brain Games and Cognition guide.
Frequently asked questions (FAQ)
What is the average human reaction time?
Simple visual reaction time is typically around 200-270ms. Under 250ms is fast, and under 200ms is very fast. This varies with individual differences and the measurement environment, so treat it as a reference.
Why is my reaction time measured so slow?
The measured value includes not only your human reaction time but also mouse/touch input lag, monitor response time, and browser rendering delay. A wireless mouse, a low refresh-rate display, or a device busy with background tasks can add tens of milliseconds.
What happens if I click before it turns green?
Clicking while the screen is red (before it turns green) is marked as 'Too early' and is not counted in your average. Clicking again retries that round.
Does this score diagnose cognitive ability?
No. This test is a reference tool for fun and self-checking, not a medical diagnosis or an official cognitive assessment. It changes constantly with your condition, sleep, caffeine, and practice.
Related games & guides
Memory Game
Repeat an ever-longer pattern of lit tiles in order to train your short-term memory.
Number Memory Test
Memorize a number shown briefly and type it back exactly.
Brain Games & Cognition
A guide covering reaction time, memory, and focus in one place.
Brain Games Home
See every brain game at a glance.
Last updated: 2026-06-25