Reaction Time Test: What’s Your Reflex Age?

How fast are your reflexes? This free reaction time test measures your simple and left/right choice reaction times in about a minute, then places them on published age norms to estimate your reflex age. Tap, click or use the space bar, then try to beat your best tomorrow.

How the Reflex Age Test works

Round 1, simple reaction time. The box turns green after a random wait of 1.5 to 4 seconds, so you cannot guess the timing. Tapping before green is a false start and that try is repeated. Anything faster than 100 ms is also treated as a guess, because people cannot genuinely react that quickly to a visual signal. We report the median of your 5 tries, which ignores one lucky or sleepy attempt.

Round 2, choice reaction time. A target appears on the left or right (4 of each, in random order) and you hit that side. Choosing adds decision time, and this kind of reaction time slows more with age than simple reaction time does. We use the median of your correct answers, and you need at least 6 of 8 right for the round to count toward your reflex age.

Reflex age. We compare your medians with the age norms in the table below, from a computer-based reaction time task tested on 150 adults aged 18 to 80 (Deary, Liewald and Nissan, 2011). That study used a 4-choice task, so we estimate left/right norms halfway between its simple and 4-choice times. Hick’s law says decision time grows with the logarithm of the number of choices, and 2 choices sits halfway between 1 and 4 on that scale. Each of your times is converted to the age whose average matches it, and the two ages are blended (40% simple, 60% choice, because choice time tracks age more closely). Reflex ages run from 20 to 80+. The “wobble” is how far your result could shift just from trial-to-trial variation.

The 20 ms device allowance. Every screen, keyboard, mouse and touchscreen adds delay before your response is registered. Web apps overestimated reaction times by about 57 to 70 ms on Android, iOS and Windows devices in one robot-timed study (Pronk and colleagues, 2020), and more on some Mac browsers. The lab computer behind the norms had its own delay: its youngest group averaged 243 ms, against roughly 200 ms for hardware-corrected simple reaction time in young adults (Woods and colleagues, 2015). We subtract the difference of about 20 ms. It is an approximation, which is one more reason to compare yourself on the same device.

Reaction time by age: what the research shows

Simple and 4-choice values are group averages on the computer version of the Deary-Liewald task, 50 adults per group. Left/right values are the midpoint of the two (Hick’s law). Between and beyond these ages the curve is drawn with straight lines.

• Simple reaction time changes slowly. In 7,130 UK adults, simple reaction time showed little slowing until around age 50, while choice reaction time slowed steadily across adulthood (Der and Deary, 2006).
• Choice time slows about three times faster. In the Baltimore Longitudinal Study of Aging, simple reaction time slowed by about 0.5 ms per year from around age 20, and a reaction task that needed a decision by about 1.6 ms per year (Fozard and colleagues, 1994).
• Age explains only a small slice. Among 1,469 adults aged 18 to 65, simple reaction time rose by only about 0.55 ms per year and age explained a small share of the differences between people (Woods and colleagues, 2015). That is why a 10 ms swing can move your reflex age by years.
• Slowing starts early. In 3,305 StarCraft 2 players aged 16 to 44, in-game response speed began to slow from about age 24 (Thompson and colleagues, 2014).

Why your score may differ from other tests

Absolute reaction times depend heavily on the equipment. Measured end-to-end latency was 48 to 276 ms on touch devices, 21 to 68 ms for desktop mice, about 77 ms for keyboards and about 235 ms for one-finger trackpad tap-to-click in one study (Casiez and colleagues, 2017). Phone touchscreens commonly add around 50 to 100 ms. Setting matters too: a large web-based study run at home recorded average simple reaction times of 479 ms in 40- to 70-year-olds (Talboom and colleagues, 2021), far slower than lab values. So compare yourself with yourself, on the same device, at a similar time of day.

How to get faster after 35 (evidence-backed)

• Protect your sleep. A meta-analysis of short-term sleep deprivation found the largest effects on simple attention and vigilance, the skill this test measures (Lim and Dinges, 2010). Staying awake for 17 to 19 hours impaired some test performance as much as a 0.05% blood alcohol level (Williamson and Feyer, 2000). Adults should sleep 7 or more hours a night (AASM and SRS consensus, 2015). Try the sleep calculator.
• Train your body to train your brain. In adults over 50, aerobic, resistance, combined training and tai chi all improved cognitive function. Moderate-to-vigorous sessions of 45 minutes or more were linked with benefits (Northey and colleagues, 2018). See VO2 max after 35 and strength training after 35.
• Play an interceptive sport. A meta-analysis found athletes faster on processing speed and attention tasks, with the largest effects in interceptive sports such as tennis, squash and other fast ball games (Voss and colleagues, 2010). Cricket, padel, badminton and table tennis all fit. Ideas: cricket fitness after 35.
• Test smart. Warm up with a round, test at a similar time of day, and look at your trend over weeks rather than one score. A slow day after a late night is information, not a verdict.

When slowing is a warning sign

This is a game, not a cognitive or medical test, and one slow score means nothing on its own. But sudden slowing, confusion, numbness or weakness of the face, arm or leg (especially on one side), trouble speaking or seeing, or a sudden severe headache can be stroke signs: call your local emergency number immediately (CDC). If you notice gradual, persistent changes in your speed, memory or coordination over weeks or months, book a check-up with your doctor.

Sources

1. Deary IJ, Liewald D, Nissan J. A free, easy-to-use, computer-based simple and four-choice reaction time programme: the Deary-Liewald reaction time task. Behavior Research Methods, 2011. PubMed
2. Der G, Deary IJ. Age and sex differences in reaction time in adulthood: results from the United Kingdom Health and Lifestyle Survey. Psychology and Aging, 2006;21(1):62–73. PubMed
3. Fozard JL et al. Age differences and changes in reaction time: the Baltimore Longitudinal Study of Aging. Journal of Gerontology, 1994;49(4):P179–P189. DOI
4. Woods DL et al. Factors influencing the latency of simple reaction time. Frontiers in Human Neuroscience, 2015;9:131. Full text
5. Hick WE. On the rate of gain of information. Quarterly Journal of Experimental Psychology, 1952;4(1):11–26. DOI
6. Pronk T et al. Mental chronometry in the pocket? Timing accuracy of web applications on touchscreen and keyboard devices. Behavior Research Methods, 2020. Full text
7. Casiez G et al. Characterizing latency in touch and button-equipped interactive systems. ACM UIST, 2017. HAL
8. Talboom JS et al. Two separate, large cohorts reveal potential modifiers of age-associated variation in visual reaction time performance. npj Aging and Mechanisms of Disease, 2021. Open access
9. Thompson JJ, Blair MR, Henrey AJ. Over the hill at 24: persistent age-related cognitive-motor decline in reaction times in an ecologically valid video game task begins in early adulthood. PLoS ONE, 2014;9(4):e94215. DOI
10. Lim J, Dinges DF. A meta-analysis of the impact of short-term sleep deprivation on cognitive variables. Psychological Bulletin, 2010;136(3):375–389. DOI
11. Williamson AM, Feyer AM. Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occupational and Environmental Medicine, 2000;57(10):649–655. Full text
12. Watson NF et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep, 2015. PubMed
13. Northey JM et al. Exercise interventions for cognitive function in adults older than 50: a systematic review with meta-analysis. British Journal of Sports Medicine, 2018;52(3):154–160. Full text
14. Voss MW et al. Are expert athletes “expert” in the cognitive laboratory? A meta-analytic review of cognition and sport expertise. Applied Cognitive Psychology, 2010;24(6):812–826. DOI
15. Centers for Disease Control and Prevention. Signs and symptoms of stroke. CDC

This reaction time test is for fun and general education, not medical advice or a cognitive assessment. Results depend on your device, browser and setting. Sudden changes in speed, speech, vision, strength or sensation need urgent medical care. Your results stay in your browser and are never sent anywhere.

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