Reaction Time Test
Respond the moment the panel lights up.
About this challenge
A free reaction time test. Wait for the panel to change colour, then press Space or tap as fast as you can. Your score is the median of your valid responses in milliseconds, measured by your browser, so your screen and input device affect it.
Choose Entry, Regular or Hard first.
What it measures
The time between a visual cue appearing and your response, as measured by your browser. Your result is the median of ten valid responses.
How the score works
Your score is the median of ten valid responses. Responding before the cue is a false start. Times under 100 ms or over 2000 ms are excluded. After 20 attempts without ten valid ones, no score is given.
Ten valid responses of 241, 255, 262, 268, 270, 274, 281, 290, 305 and 412 ms give a median of (270 + 274) ÷ 2 = 272 ms. The median ignores one slow outlier like 412 ms, which an average would not. A press before the cue is a false start and is not counted.
Entry, Regular and Hard
- Entry
- 3 practice trials, then the median of 10 valid simple responses.
- Regular
- 20 scored simple trials with a wider spread of random waits, so the cue is harder to anticipate.
- Hard
- Choice reaction: 20 trials where the cue appears on the left or right and you respond on the matching side. This measures a different thing from simple reaction time, so its scores are never compared with Entry or Regular.
Each level has its own fixed set of items and its own score, so results are only compared within the same level. How levels are designed
What Premium adds
Your basic score is always free. Premium adds: Interquartile range, trial chart and false start review. It also keeps your full history on every device and removes the ads. One upgrade covers all ten tests. See Premium
Limits
Browser response times depend on your screen, input device and system load. They are labelled device-dependent and are not a medical measurement.
For education, entertainment and general self-exploration only. These activities are not medical or psychological assessments and do not diagnose, prevent or treat any condition. Results are estimates of performance on these tasks and can be affected by practice, attention, language, your device and your surroundings. If you have concerns about your thinking, vision or hearing, consult a qualified healthcare professional.
Questions
What is a normal reaction time?
Browser results for simple reaction tasks often fall around 200 to 350 ms, but your screen, keyboard or touch screen, and browser all add delay. Compare your own results on the same device rather than with other people.
Why is my phone slower than my keyboard?
Touch screens and some displays add input and display delay before your browser sees the response. That delay is part of the measured time, which is why results from different inputs are kept apart.
Why the median and not the average?
One very slow or distracted response can pull an average up a lot. The median is the middle value, so a single outlier barely moves it.
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Made and maintained by ChowChow Labs. Content last reviewed October 23, 2026. Methodology and changelog · Report a problem