Speed
Reaction Time Test
Click the moment the screen turns green. Five attempts, and your score is the median.
Take the test →about 40 seconds · no sign-upReaction · Memory · Attention
Free brain tests you can take right now.
Free brain tests and puzzles with no sign-up: measure your reaction time, digit span and attention, see how your result compares, and keep your own history in the browser.
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All tests →Short-term memory
Digit Span Test
Digits appear one per second. Type them back in order — the list grows until you miss twice.
Take the test →about 150 seconds · no sign-upAttention
Schulte Table
Find the numbers 1 to 25 in order, as fast as you can, without hunting around the grid.
Take the test →about 60 seconds · no sign-upLatest articles
Browse all →Featured
What the Schulte Table Actually Measures
The Schulte Table measures visual scanning speed, peripheral attention, and processing speed — not memory or intelligence. Why this test shows a result summary instead of a percentile, and how to read your own progress.
Guide
What Is an N-Back Test and Why Researchers Use It for Working Memory
In an n-back task you watch a stream of items and flag any that match one from N steps earlier. It's a standard way researchers measure working memory — not a proven way to improve it.
Guide
What Does Your Percentile Actually Mean?
Scoring in the 80th percentile doesn't mean you got 80% right — it means you did better than 80% of the people you're being compared against. The comparison group is the whole story.
Guide
Visual Memory Test: What It Measures and What a Good Score Looks Like
A visual memory test asks you to remember a pattern of lit-up tiles and reproduce it. What it measures, why scores vary so much day to day, and why no single result is a verdict on your memory.
Guide
The Stroop Effect: Why Reading the Word Is Harder Than Naming the Color
Say "blue" when the word BLUE is printed in red ink, and you slow down. The Stroop effect shows just how automatic reading is, and why it fights with the simple task of naming a color.
Guide
Do Brain Training Games Actually Work?
You get better at the game you practise. Whether that carries over to anything else is still unsettled — and one company paid two million dollars for overstating it.
Guide
Why the Same Test Gives You a Different Result Every Time
Your own attempts vary by about 40 milliseconds even within a single sitting. That is measured, expected, and the reason one run should never be treated as your number.
Guide
How Many Numbers Can You Hold in Your Head?
Six or seven digits for most adults — and the famous “seven” is a rule of thumb about chunks, not a hard limit. What the number depends on and how to measure your own.
Guide
Is a 250-Millisecond Reaction Time Bad?
A 250-millisecond result is close to ordinary for an adult, and part of it belongs to your screen rather than to you. Where the number sits, why it moves, and what it cannot tell you.