What you get, and what you do not
At the end of a full run you have eight numbers. A reaction time. An aim speed per target. How many digits you held. A sequence level, a visual memory level, a chimp test board size, how many words you kept straight, and a color level. One of them carries a percentile: sequence memory, placed on forward Corsi span from Facchin and colleagues. Reaction time cites the Woods laboratory distribution as reference but wears no percentile, because device delay varies too much between setups for that to be honest. The other six show your score alone. No published study matches the way they are played here, and we would sooner show you nothing than a number we made up. Every source is listed on the methodology page.
What you will not get is a single combined figure. We could average the eight into one "brain score". It would be more shareable than eight separate results, and it would mean nothing. The eight tests measure skills that are only loosely linked. And to average a millisecond, a digit count and a level, you have to invent weightings no research supports. A composite would look authoritative precisely where it is least justified.
Why these eight, and why this order
The order isn't arbitrary. Reaction time comes first. It suffers most from tiredness and depends least on tactics, so you want it while you are fresh. Aim comes next because it is the other speed test. Keeping the two together means your brain only has to switch gears once.
Then the memory block: numbers, sequence, visual, chimp, verbal. These five sit in the middle on purpose. Memory works best when you are warmed up but not worn out, and the middle of the run is where that window is widest. They start with digits, move into space, and reach the chimp test, which asks for order on top of position. Verbal memory closes the block because it is the only test that keeps growing while you play: every word you answer joins the pile you have to keep straight. That spreads the load instead of hitting the same system five times in a row.
Color discrimination goes last for a specific reason: it is the only test where staring is actively harmful. Your retina adapts to a field of similar color within seconds, so the test rewards fresh eyes on each level, not accumulated concentration. Putting it last has a bonus: if the run has tired you out, the test that needs the least focus is the one that takes the hit.
What we measured while building this
None of what follows is in a paper. It is what we found while making the tests work in a browser, and it changes how much your numbers mean.
A browser adds roughly 80 milliseconds you did not spend. The screen has to refresh. The computer has to notice your click. The page has to receive it. Each step adds delay that has nothing to do with you. Anwyl-Irvine and colleagues quantified this — and because the delay differs from setup to setup, this site does not convert your reaction time into a lab percentile at all; the research numbers stay on the page as reference. A browser test and a lab test are simply not the same measurement. Sites that compare raw browser times against lab averages make everyone look slower than they are.
A background tab destroys timing. Browsers deliberately throttle timers in tabs you are not looking at, to save battery. We ran all the tests by machine in a background tab. Rounds that normally take two seconds blew past a twenty-five second limit. The effect is large enough that a measurement taken while you were reading something else in another tab would be worthless. That is why every timed test here refuses to start while the tab is hidden. You get a notice, not a quietly recorded bad number.
Your screen is part of two of these tests. Color discrimination depends on panel quality, brightness and ambient light more than it depends on the player. And on a narrow phone, a six-by-six grid simply cannot give every tile a full-size touch target. The maths does not fit, so tiles shrink on small screens. We measured this and now size the grid from the real width of the panel, so tiles never overlap. An earlier version had tiles overlap by three pixels, and a click near an edge could land on the wrong square. If you play the grid tests on a phone and a desktop, you are playing two slightly different games.
Making your run comparable to your next one
The comparison that tells you most is you against yourself. That only works if you keep the conditions the same. Use the same device. Use the same pointer too. A mouse, a trackpad and a touchscreen give truly different numbers, and the gap between them is bigger than your day-to-day ups and downs. Keep the tab in the foreground for the whole run, which the tests now enforce. And try to play at a similar time of day. Alertness rises and falls through the day, and that moves reaction time more than an evening of practice will.
Then run it more than once. Single results are noisy across all eight tests, and the shape of five runs tells you something a single run cannot. Your scores are kept in this browser only, so the history builds up on the device you actually use.
Frequently asked questions
Can I stop partway through?
Yes. The run records each test as you finish it, so you can stop after any test and the scores you already have are kept. Coming back to the run page offers to resume from the first test you have not done.
Do I have to do the full run to see percentiles?
No. Each test works on its own and shows the same result panel, curve and percentile whether you reached it through the run or directly. The run exists to collect the eight into one summary, not to unlock anything.
Where do my scores go?
Your personal records stay in this browser's local storage. There is no account, clearing site data clears them, and a different browser or device starts from scratch. Two things are sent out: an anonymous statistics record when a test finishes (game, mode, score, device class, language, date — nothing that can identify you), and, only if you choose to submit one, the nickname and score for a leaderboard.