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Number Memory

How many digits can you hold at once

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What is a number memory test?

A number appears on screen for a few seconds, disappears, and you type it back. Get it right and the next number is one digit longer. The digit count you fail at is your score, and it is one of the cleanest measures of verbal working memory span there is.

The famous figure here is seven, plus or minus two, from George Miller's 1956 paper on the limits of short-term memory. It has been refined a great deal since, and the modern view is that pure capacity is closer to four chunks, with anything above that coming from grouping. That distinction is exactly what this test exposes: almost everybody stalls around seven digits until they start deliberately grouping, at which point the ceiling moves.

How to play

  1. A number appears. Memorise it before the timer runs out.
  2. Type it back and submit.
  3. Each correct answer adds one digit.
  4. One wrong answer ends the run.

What counts as a good score?

Seven digits is the median, which is not a coincidence given that phone numbers were designed around that limit. Nine puts you in roughly the top quarter, eleven in the top ten percent, and anything past thirteen almost always means a rehearsed chunking or memory-palace technique rather than raw span.

How to remember more digits

  • Group into pairs or threes. 4 9 2 7 3 1 is six things. 49, 27, 31 is three. This alone typically adds two or three digits.
  • Read it in a rhythm. Chanting the groups gives the sequence a shape, and the shape is easier to recall than the digits.
  • Attach meaning. Years, ages, house numbers. A group that means something is stored far more cheaply than one that does not.
  • Rehearse right up to the moment you type. Working memory decays in seconds without refreshing, so the silent pause before typing is where most runs are lost.
  • Type fast and do not double-check. Re-reading what you have typed disrupts the rehearsal that is holding the rest of the number.

The other four tests

Number Memory is the verbal counterpart to Sequence Memory, which tests the same capacity spatially. Most people are clearly better at one than the other, and the gap is worth knowing about. The Chimp Test is harder than both. Reaction Time and Aim Trainer measure speed rather than memory, and all five keep separate best scores in your browser.

Frequently asked questions

What is the average number memory score?

Seven digits. Nine puts you in roughly the top quarter, eleven in the top ten percent, and past thirteen usually indicates a deliberate memorisation technique.

Why is seven digits the limit for most people?

It traces back to George Miller's 1956 finding that short-term memory holds about seven items. Modern work suggests raw capacity is closer to four chunks, with anything beyond that coming from grouping digits together.

Is chunking cheating?

No, and it is the entire point. Everyone scoring above about nine is chunking, whether consciously or not. The test measures how well you can hold and reproduce a number, not how you manage it.

How long do I get to look at the number?

A few seconds, scaled to the length. The timer is shown so you know how much is left.

Can I use a pen and paper?

You can, but the score stops meaning anything. The percentile compares you against people memorising it.

Is my score stored anywhere?

Only in your own browser. There is no account and nothing is sent to a server.

Is there a daily challenge?

Yes. The daily gives everyone the same board, generated from the date, and it resets at midnight UTC. Your result is recorded and the strip above the game shows your last seven days and your current streak. Nothing is sent to a server, so the streak lives on your own device.