Hold It in Mind
Carry the last N letters in order and update the list with every new one. Exactly what working memory does.
Press on a Match
Tap the area when the letter matches the one N steps back; catching it fast adds a speed bonus.
Pick Your Level
1-back is a warm-up, 2-back the standard, 3-back for masters. Each level competes on its own leaderboard tab.
What Is the N-Back Test?
N-back is the most established working memory task in cognitive science: letters appear one at a time, and your job is to decide whether the current letter matches the one you saw N steps back. In 1-back you compare with the previous letter, in 2-back with two letters ago, in 3-back with three. What makes it hard is not memorizing but updating: with every new letter you must add one item to the N-item list in your head, drop the oldest, and compare at the same time. This "hold, update, compare" loop is exactly what working memory does when you study, calculate in your head or follow a conversation.
The task was introduced by Wayne Kirchner in 1958 and has been a standard of both laboratory research and brain imaging ever since. N-back performance is among the tasks most consistently linked to fluid intelligence — the capacity for reasoning and problem solving — which also made it the star of "brain training" research. The version here is the classic single-channel (letter) n-back; the match rate is fixed in every round, so scores are fairly comparable across rounds and players.
How It Works
- Pick your N level on the start screen: 1-back is a warm-up, 2-back the standard measure, 3-back for masters. Each level competes on its own leaderboard tab.
- Press "Start test" and a short get-ready screen appears; then the letters begin.
- The first N letters are for memorizing — there is nothing to compare with yet, so they are not scored and a "Memorize" hint shows below.
- Each letter stays for about 1.4 seconds and the rhythm never stops; feedback appears in the line under the letter without interrupting the flow.
- When the letter matches the one N steps back, tap the area or press Space. The earlier you press, the bigger the speed bonus (60 base + up to 40).
- Pressing without a match costs 50 points; a missed match carries no penalty but lowers your accuracy.
- At the end you see your total score, accuracy and average reaction time on matches.
- Your score joins the leaderboard of your chosen N level; later rounds only update it when they are higher.
Tips for a Better Result
- Rehearse the letters silently. Most people solve n-back through the auditory loop, not visually: repeating "K-T-K" in your head keeps the sequence far more stable.
- Think of a moving strip, not single items. Instead of memorizing letters one by one, slide the whole strip one step with every new letter. The updating habit matters more than raw memorizing.
- Master 2-back before trying 3-back. Difficulty multiplies with every step of N; switching too early only builds a false-alarm habit.
- Do not wait for a match. When matches come is random; pressing because "one is due" is the most common way to lose points. When unsure, hold back — the math is on your side.
- Take the first N letters seriously. Whoever daydreams through the memorize phase fails the first real comparisons. Start building your mental list immediately.
- Train short and often. N-back is exhausting; a few short rounds a day beat one long session.
- Do not judge yourself when tired. Working memory reacts quickly to sleep loss and mental fatigue; a bad evening round is not your real level.
- Fix accuracy before speed. Settle at 85%+ accuracy first, then chase the bonus; the reverse order multiplies false alarms.
What It Measures and Builds
- Working memory capacity: Holding information briefly while operating on it — exactly what n-back measures, and one of the strongest cognitive predictors of school and work performance.
- Memory updating: Adding to and dropping from the list at every step is the standard measure of the "updating" component of executive functions.
- Interference resistance: Not saying "match" to a letter you saw recently but not exactly N steps back trains resistance to distracting memories.
- Sustained focus: Because the rhythm never stops, one moment of drift breaks the chain; the task strains attentional continuity too.
- The fluid intelligence link: N-back performance correlates consistently with the capacity to solve novel problems, which made the task a favourite of researchers.
Frequently Asked Questions
What does the n-back test measure?
Working memory: the ability to hold information briefly while updating and comparing it with every new stimulus. Because it requires holding plus processing at once, it differs from simple memorization tests.
Which N level should I start with?
2-back. 1-back is easy for almost everyone and has little measuring power; 3-back is demoralizing without practice. Research also uses 2-back as the standard starting point.
What is a good score?
In a round of 21 scored stimuli, above 400 is good and above 550 very good for 2-back; the theoretical ceiling is 700. The same scores are worth much more in 3-back — which is why each level has its own leaderboard.
Does n-back training raise intelligence?
Contested. Some studies reported gains in fluid intelligence after n-back training; larger reviews find the gains mostly limited to the task itself. What is certain: your n-back performance improves clearly with practice.
Why are the first letters not scored?
In the first N letters there is no "N steps back" to compare with yet; they exist only for memorizing. Scoring starts with the first letter where a real comparison is possible.
What happens if I miss a match?
A missed match costs no points, it only lowers your accuracy. Pressing without a match costs 50 points — so when unsure, waiting is mathematically the better bet.
Why letters and not shapes or positions?
Letters are the standard stimulus of the classic single-channel n-back: instantly readable, easy to rehearse silently and recognizable across languages. Position-based (spatial) n-back is a separate variant.
Is working memory different from memory?
Yes. Long-term memory stores information; working memory holds a few seconds of information while operating on it — the workspace of mental arithmetic, sentence building and reasoning.
Is the test free? Do I need an account?
Completely free; no membership, download or registration — it runs right in the browser. A nickname is all you need for the leaderboard.
How is the score calculated?
Catching a match earns 60 points plus a speed bonus (up to 40); pressing without a match costs 50. The number of matches is fixed every round, so scores are comparable across rounds.
Ready When You Are
Press "Start test" above and measure right away — no sign-up, completely free.
For other faces of memory try the Memory Test and Memory Cards; for the attention side take the Attention Test or solve the free IQ test.