What these tests are — and what they are not
Each of these is a short, self-scoring version of a task that psychologists use to probe one narrow ability: how fast you answer a signal, how much of a pattern you can hold in mind. They are genuinely useful for one thing — watching your own numbers over time — and genuinely useless for another: comparing yourself to a stranger, or to a table of averages with no method behind it.
They are not medical or diagnostic tests. A browser cannot control your screen, your posture, your distractions or your sleep, and every one of those moves the result more than most real differences between people would. If something about your memory or attention is worrying you, that is a conversation for a doctor, not for a web page.
What we can do is be straight about the machinery. Every test here has a page explaining what it measures, what inflates or deflates the number, and where the task comes from, with references you can go and read.
How to get a result worth comparing
- Same device, same input. A mouse beats a finger; a 120 Hz screen beats a 60 Hz one. Switching devices between attempts makes the comparison meaningless.
- Take it more than once. Your first attempt measures unfamiliarity as much as ability. Most people improve for two or three sessions before settling.
- Same rough time of day. Alertness swings across a day by more than you would think.
- Look at the trend, not the record. One good run is luck. A direction over a couple of weeks is information.
Your results stay with you
Scores are written to your browser's local storage and nowhere else. There is no account, no upload and no tracking of how you did. Clearing your browsing data clears them, and results from your phone will not appear on your laptop.