Seven of these measure how your attention, memory and speed are running right now. Not how clever you are: a different question, and a more useful one, because unlike the first it actually changes.
One asks how you feel instead of measuring anything, because that is a different kind of evidence and worth having next to the rest. One is a reasoning test, which barely moves whatever sort of day you are having. Both say so on their own pages before you start.
Free, no account, nothing to install. Every test is a real instrument from the research literature, not a game with a score bolted on.
Under five minutes together, and they are the three that move most with how you slept and what you have eaten. If you only ever take part of this, take this part.
Tap the moment the box lights up. The only one of these you cannot get better at with practice, which makes it the one worth taking daily.
90 secTake it →Processing speedNine symbols, nine digits, one lookup table and a clock. Scores how much you fade across the run, not just how fast you started.
90 secTake it →Impulse controlTap for circles, sit still for squares. Three quarters are circles, so tapping becomes a habit, and then the test begins.
100 secTake it →FocusName the ink, not the word. Ninety years old and still one of the cleanest measures of whether you can suppress the obvious wrong answer.
2 minTake it →Spatial memoryBlocks light up in order and you tap them back. There are no words in it anywhere, which is exactly why it finds something digit span cannot.
3 minTake it →Mental flexibility1 to A to 2 to B, twenty five times. Counting is easy, the alphabet is easy, swapping between them is the thing being measured.
3 minTake it →Working memoryDigits forwards, then backwards. You were told memory holds seven things. Backwards is where you find out what it really holds.
4 minTake it →MoodEight words and a scale. The only page here that asks you instead of measuring you, which makes it the fastest and the easiest to answer dishonestly.
1 minTake it →ReasoningA grid with one piece missing and a rule you have to find. The only test here that is not really about today. It reads about the same whether you slept or not.
5 minTake it →More will be added over time. Anything new has to earn its place: a real instrument from the literature, a score that means something on its own, and a page that says plainly what it cannot tell you.
A single score off a single run tells you almost nothing. Four rules turn these from a novelty into something you can actually read.
Your first score is a baseline, not a verdict. What matters is the direction across several sessions. Every one of these pages says the same thing on its own results screen, and it is the single most ignored instruction here.
Your alertness at 10am and at 4pm belong to two different people. Comparing across times of day tells you about your body clock, not about your sleep or your focus.
A laptop keyboard beats a phone by tens of milliseconds before your brain is involved. Screen size also changes the memory tests. Switch devices and you have broken your own comparison.
Leaderboards are entertainment. Between two people, most of the difference is hardware, age and how hard they were trying. Between two of your own runs, most of it is you.
Every test here comes from real research, and every one of them has real limits. Both of those are true at once and the second gets left out far too often.
None of these diagnose anything. Not ADHD, not a sleep disorder, not cognitive decline. They are screening-style tasks running in a browser, on unknown hardware, with nobody watching to check you took them seriously. A low score means something is worth looking at, never what.
Clinical versions are administered by a person, at a controlled pace, on standard equipment. Published norms come from those conditions and do not transfer here. Where a page mentions a typical adult range, treat it as orientation, not a grade.
Sleep, caffeine, mood, the hour, noise in the room, how much you care. That sensitivity is what makes these useful for tracking yourself and useless for ranking anyone against anyone else.
Nothing here is a test of how clever you are. These are state measures, built to move with how your day is going. If they were measuring something stable about you, they would be useless for the thing they are actually for.