Log a score. See your trend. Nothing leaves your browser.
A single best score tells you almost nothing — it is dominated by luck, mood and how warmed up you were. A trend line over several runs tells you whether you are actually improving. This logs your scores, computes the trend, and keeps all of it in your own browser.
Any single run swings with sleep, caffeine, time of day and whether you warmed up. Chasing a personal best means you mostly measure your luckiest day, which moves rarely and tells you nothing in between.
Five-run rolling averages move smoothly and honestly. This shows you both, plus a least-squares slope so 'improving' is a computed claim rather than an impression.
Reaction and timing scores depend heavily on hardware. Display refresh rate and input lag are worth real milliseconds, so a phone result and a desktop result are different measurements. Log them separately, or always use the same device.
Memory span scores depend on presentation speed, which is why a number from another site sits on a different scale from one here. Compare only within this site.
Record the conditions when they change. A run after a bad night is not a data point about your ability.
In your browser's local storage. Nothing is sent to us, there is no account and we cannot see it.
That also means clearing your browsing data deletes it, and it does not sync between devices or browsers. The CSV export exists so you can keep a copy that survives both.
Yes. It is stored in your own browser and never sent anywhere. There is no account and we cannot see it.
A single best run is mostly luck — it swings with sleep, caffeine and warm-up. A five-run average moves smoothly and shows real change.
Yes, as a CSV you can open in any spreadsheet. That is also the only way to move them between devices, since local storage does not sync.
Local storage is per-browser and per-device. Export the CSV and import it wherever you need it.
No. There are no accounts anywhere on this site.