Guides
The tests give you a number. These explain what the number is made of, what moves it, and which claims about it are worth believing.
- Is an online reaction time test accurate?Where the extra 80 ms comes from, and what we measured building this.
- How to improve your reaction timeWhat works — sleep, timing, warm-up, hardware — and what does not.
- Do brain training games actually work?Near transfer, far transfer, and why this site measures instead of trains.
- What is a good reaction time?Every score from under 150 to over 360, on the screen scale and the lab scale, with the badge each one earns.
- Average reaction time by ageLab studies say 0.55 ms a year, browser data says 7. Why both are right, and what to expect at your age.
- Reaction time on a phone vs a mousePhones add 35 to 140 ms of screen and touch delay. Which score to trust, and how to compare fairly.
- How we screen leaderboard nicknamesA slur got through our filter. What replaced it, and why over-blocking costs more.
Why these exist
A test result on its own invites the wrong conclusion. Two hundred and eighty milliseconds sounds slow next to a published average of 231, until you know that a browser adds roughly 80 ms nobody spent, that a 60 Hz screen costs about 8 ms more than a 144 Hz one, and that your own trials scatter by around 40 ms regardless. The guides carry the context that makes a number honest, including the parts that make our own numbers look less impressive.
Everything factual here is either linked to its source or was measured by us while building the tests, and where we measured it ourselves the page says so. If something is wrong, write to ysc9550@gmail.com and it gets corrected. Ready to get a number first? Start with the reaction time test or the full benchmark.
How to use these alongside the tests
Take a measurement first, then read. A number in front of you makes the context concrete: once you have seen your own median and the spread of your five rounds, the claim that within-person variability runs around 40 milliseconds stops being a statistic and starts explaining the run you just did. Start with the reaction time test, which takes about thirty seconds, or the full benchmark if you want all eight.
Then read the measurement guide before you compare yourself with anyone. It is the one that changes how you read every other number on the site, because it explains why the figure on your screen is not the figure in your nervous system, and why a laptop result and a desktop result are two different measurements rather than two attempts at the same one.
The practice guide is worth reading before you decide you are slow. Most of what separates a disappointing run from a good one is sleep, time of day, warm-up and equipment rather than anything permanent about you, and those are all things you control. The evidence guide is the sceptical one: it explains why we call this site a measurement tool and not training, and what the research actually supports when someone tells you a game will make you sharper.
Which guide answers what
Seven guides, seven different questions. If you arrived with one of these in mind, start there rather than at the top.
- "Why is my number so different from the one in the study?" The measurement guide takes the chain apart: the screen, the mouse, the operating system, the browser event loop. It also carries what we measured ourselves while building this, including the timing bug that made our own early numbers wrong.
- "Can I actually get faster?" The practice guide separates the things that move your score from the things that only sound like they do. Sleep and time of day move it. Hardware moves it. Most of what gets sold to gamers does not.
- "Will doing this make me smarter?" The evidence guide is the sceptical one, and it argues against our own product category. Practising a test makes you better at that test. Whether anything spreads beyond it is contested, and we would rather say so than sell you a training plan.
- "Is my number good?" The scores guide puts every reaction time from under 150 to over 360 in one table, explains why laboratory averages read about 80 ms faster than the screen, and answers the 186, 200, 213, 250 and 300 questions one by one.
- "How much slower will I get?" The age guide puts six studies in one table, from 0.34 to 7 ms per year, and explains why laboratory and browser datasets disagree by ten times without either being wrong.
- "Why is my phone score worse than my laptop score?" The devices guide takes the touchscreen chain apart, puts the measured 35 to 140 ms of phone hardware delay next to the desktop figure, and explains why the two histories should never be compared with each other.
- "Who is watching the leaderboard?" The moderation guide explains how nicknames are screened, why blocking too much is the more expensive mistake, and which evasions we deliberately left open.
What we will not do here
We will not publish a number without saying where it came from. Every figure in these guides is either linked to a peer-reviewed source or was measured by us while building the tests, and the ones we measured ourselves are labelled as ours rather than dressed up as research. Where no published norm fits one of our tests, the test shows no percentile at all rather than an invented one. Seven of the nine tests are in that position, and the methodology page names them.
We also will not tell you that repeating these tests will improve your cognition, because the evidence does not support it. What repetition reliably does is make you better at these particular tests, which is useful to know when you look at your own history and see a steep early improvement.