How the n-back test works
A square lights up on a three by three grid, one position at a time, a little under two seconds apart. Your job is to press Match whenever the square is in the same place it was N steps back. You start at 1-back, where you just compare each square with the one before it. Score 80% or better on a level and you move up: at 2-back you compare with the square two steps ago, at 3-back three steps ago, and so on.
What makes it hard is that the answer keeps changing. Most memory tests ask you to hold something still; the n-back test makes you hold a moving window, adding each new square and dropping the oldest one, while deciding about every square as it arrives. That constant updating is what psychologists call working memory, and the n-back has been one of the main ways of measuring it since Wayne Kirchner introduced it in 1958.
Your score is the highest level you passed, plus partial credit for how close you came on the next one. Green flashes mean a correct match, red means you pressed on a square that was not a match, and amber means you missed one.
What counts as a good level
| Level reached | Standing |
|---|---|
| Under 2 | Warming up |
| 2 – 3 | About average |
| 3 – 4 | Above average |
| 4 – 5 | Strong |
| 5 and above | Exceptional |
These ranges are a first estimate and will be refined as more people take the test. Scores rise noticeably with practice, so compare yourself with your own first run as well as with everyone else.
How to get further
- Say the positions to yourself. Naming each square, such as top left or middle, turns the task into a short spoken list, which most people hold more easily.
- Keep a running list, not a picture. At 3-back, keep the last three positions in order and drop the oldest each time a new one appears.
- Decide on every square. Leaving a match unpressed costs as much as pressing on a non-match, so commit either way.
- Do not chase lost squares. If you lose the thread, let it go and rebuild from the next few squares rather than freezing.
- Practise little and often. A few short runs a day improve n-back faster than one long session.
For other kinds of memory, try the Number Memory Test, the Sequence Memory Test or the Chimp Test.
Frequently asked questions
What is an n-back test?
A working memory test introduced by the psychologist Wayne Kirchner in 1958. Items appear one at a time and you respond whenever the current one matches the one N steps back. At 1-back you compare each square with the one just before; at 3-back you have to keep the last three in mind and keep updating them as new ones arrive.
What is a good n-back score?
Most people pass 2-back and reach somewhere around level 2 to 3 here. Passing 3-back puts you above average, and 4-back or higher is strong. These ranges are a first estimate and will be refined as more people take the test.
Does n-back training make you smarter?
A well known 2008 study suggested that practising a version called dual n-back could raise fluid intelligence, and it made the test famous. Later research has been much more mixed: practice reliably makes you better at n-back itself, but evidence that it improves general intelligence is weak. Treat it as a good measure of working memory and a fun challenge.
What counts towards my accuracy?
Every square after the first N. A match you pressed, or a non-match you left alone, counts as right. About a third of the squares are matches, so you cannot pass by never pressing or by pressing all the time.
What does a score like 3.4 mean?
The whole number is the highest level you passed. The decimal is partial credit for how close you came on the next level, so 3.4 means you passed 3-back and got a fair way through 4-back. It lets you see progress before you pass the next level.