Brain Games · Memory
Digit Span Test
A number appears for a moment: 2 seconds plus half a second per digit. Type it back. Two tries at each length.
In short
What does a digit span test measure?
A digit span test measures how many digits you can hold in mind and repeat back in order. Most adults manage about 7 forward, and fewer backward. It is also called a number memory test, and a version of it sits inside professional IQ tests such as the WAIS.
Below: the four modes, how long each number shows, and how digit span fits into an IQ score.
How to play
Four ways to test your digit span
Pick a mode at the top and press Start. The number grows by one digit each time you get it right, and the result shows exactly where you slipped.
Flash
How many digits you hold after one look.
- A number appears for 2 seconds plus half a second per digit: 5.5 seconds for 7 digits.
- It disappears. Type it back on the keypad or with the number keys.
- Right: one digit more. Two misses at the same length end the run.
Forward
Holding digits in the order you heard them.
- The digits appear one at a time, one a second.
- Type them back in the same order.
- Each right answer adds a digit; you get two tries at every length.
Backward
Holding digits while you turn them around.
- The digits appear one at a time, one a second.
- Type them back in reverse: the last digit first.
- Backward spans are usually shorter than forward ones, for everyone.
Sequencing
Sorting digits in your head while you hold them.
- The digits appear one at a time; no digit appears twice.
- Type them from the smallest to the largest.
- This mirrors the sequencing part of professional digit span tests.
Your score
How long each number shows
Flash shows the whole number for 2 seconds plus half a second per digit, the rule in UK Biobank's online numeric memory test. Forward, Backward and Sequencing show one digit a second.
| Number length | Shown for |
|---|---|
| 3 digits | 3.5 s |
| 5 digits | 4.5 s |
| 7 digits | 5.5 s |
| 9 digits | 6.5 s |
| 12 digits | 8.0 s |
Scores from different sites only compare when the timing is the same. Compare yourself with yourself.
A tip
Chunk the digits
Grouping is the best-known way to hold more. It helps you use your span; it does not make your memory bigger.
- Group the digits in threes, like a phone number: 481 572 903.
- Say each group in your head as you see it.
- For Backward, read the groups back from the end.
- For Sequencing, note the smallest digits first as they appear.
Number memory
Is a number memory test the same as digit span?
Nearly. A number memory test flashes one long number and asks you to type it back; a digit span test shows the digits one by one. Both use the same short-term store. Our Flash mode is the first, Forward the second.
Forward
Repeat the digits in the order you saw them. This is short-term memory at its simplest: hold the list, then play it back.
Backward and Sequencing
Say them in reverse, or from smallest to largest. Now you hold the digits and work on them at once, which is what psychologists mean by working memory.
Why digits?
Almost everyone knows them, they carry little meaning and there are only ten. That makes a fair, simple test of how much you can hold.
Average span
What is the average digit span?
The average digit span is not exactly seven. Verified adult averages run from about 5.3 to 6.9 digits forward, depending on the language and the procedure. Backward spans are a little shorter.
Verified average digit spans, by study
| Group | Forward | Backward |
|---|---|---|
| 36 English speakers, University of York, mean age 21 | 6.94 | not tested |
| 36 Mandarin speakers, same study, digits in Mandarin | 8.84 | not tested |
| The same Mandarin speakers, digits in English | 5.77 | not tested |
| 225 healthy Italian adults | 5.30 | 4.54 |
York: Mattys, Baddeley and Trenkic (2018). Italy: Priftis and colleagues (2025). Neither is a Wechsler score.
Language changes the number
The same people recalled 8.84 digits in Mandarin and 5.77 in English. A test in a second language can understate your span.
Education more than age
In 784 adults aged 60 to 90, education explained 29.8% of the differences in forward span, and age only 1.1% (Choi and colleagues, 2014).
Seven is a rough rule
Miller’s “seven, plus or minus two” (1956) was a rough estimate. Cowan (2001) puts the limit at about four chunks when items cannot be grouped.
Read your score
How do you read your digit span score?
Compare your span with your own earlier scores on the same mode. One low score is not a diagnosis: tiredness, stress, noise and the language of the digits all move it.
A worked example
Say you see 5-8-2-9. Forward, you type 5829. Backward, you type 9285. Sequencing, smallest to largest, you type 2589.
Forward is easier
Forward span is mostly storage. Backward and Sequencing add mental work, so most people score lower on them. That is a working memory test.
In the WAIS-5
Since 2024 the adult Wechsler test has Digit Sequencing as a main subtest, Digits Forward and Backward as extra ones, and a new Running Digits task.
Skills
What the test uses
Working memory
Holding digits and working with them at the same time. Professional IQ tests such as the WAIS include digit span in their working-memory score.
Attention
Taking in every digit as it appears. A moment's lapse loses a digit.
Short-term memory
Keeping a sequence in mind for a few seconds, the oldest measure in memory research.
And IQ
How is digit span used in an IQ test?
Wechsler IQ tests, such as the WAIS-5 for adults, use digit tasks to build their Working Memory index. That index is one of five areas, next to verbal, visual, reasoning and speed scores.
Working memory and reasoning are closely linked: in a reanalysis of 14 data sets they shared about half their variance (Kane and colleagues, 2005). They are still not the same thing. A long digit span helps, but only an online IQ test that covers every area gives an IQ score.
The five areas of a modern IQ test
- Verbal comprehensionWord knowledge and reasoning in words
- Visual spatialSeeing and turning shapes in your mind
- Fluid reasoningFinding the rule in a new problem
- Working memoryHolding information and using itClosest to this game
- Processing speedQuick, accurate simple work
The five primary index areas of the WISC-V (children, 2014) and the WAIS-5 (adults, 2024). See WAIS-5 index scores explained.
FAQ
Digit span test: questions people ask
What is a digit span test?
You see or hear a string of digits and repeat it. The string grows by one digit after each right answer, and your span is the longest string you get right.
What is a good digit span?
The classic estimate is that people hold about seven items, plus or minus two (Miller 1956). Backward spans are usually shorter. The fairest comparison is with your own past scores on the same mode.
Is digit span related to IQ?
Digit span is one of the working-memory tasks in professional IQ tests such as the WAIS. On its own it measures one skill; a full IQ test combines memory with reasoning and speed.
What is the difference between forward and backward?
Forward asks you to repeat the digits in order. Backward asks for them in reverse, so you have to hold and reorder them at once, which is harder for everyone.
How long is each number shown?
In Flash, 2 seconds plus half a second per digit: 5.5 seconds for 7 digits. In Forward, Backward and Sequencing, one digit a second (0.7 seconds on, 0.3 off).
Why do I get two tries?
One slip should not end a run, so you get two tries at each length, each with a new number, as in research versions of the test. Two misses at the same length end it.
Can you improve your digit span?
Practice and chunking (grouping digits in threes) make you better at the task. The underlying memory capacity changes much less.
Is a low digit span a sign of a memory problem?
Not on its own. Sleep, stress, practice and the language of the digits all change it. If you are worried about your memory, talk to a doctor: only a full assessment can tell.
Can I challenge a friend?
Yes. After a run, send the link: your friend starts on the same numbers in the same mode and sees both spans.
Is it free?
Yes. It is free to play, with no signup, and your scores stay in your browser.
Sources
The research behind this page
- Kane, M. J., Hambrick, D. Z., & Conway, A. R. A. (2005). Working memory capacity and fluid intelligence are strongly related constructs. Psychological Bulletin, 131(1), 66–71. doi:10.1037/0033-2909.131.1.66
- Mattys, S. L., Baddeley, A., & Trenkic, D. (2018). Is the superior verbal memory span of Mandarin speakers due to faster rehearsal? Memory & Cognition, 46(3), 361–369. doi:10.3758/s13421-017-0770-8
- Priftis, K., et al. (2025). Digit span and bisyllabic non-word span: Italian norms. Journal of Neuropsychology, 19(3), 520–540. doi:10.1111/jnp.12420
- Choi, H. J., Lee, D. Y., & Seo, E. H. (2014). A normative study of the digit span in an educationally diverse elderly population. Psychiatry Investigation, 11(1), 39–43. doi:10.4306/pi.2014.11.1.39
- Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24(1), 87–114. doi:10.1017/S0140525X01003922
- Winter, E., Trudel, S., & Kaufman, A. S. (2024). Wait, where’s the Flynn effect on the WAIS-5? Journal of Intelligence, 12(11), 118. doi:10.3390/jintelligence12110118
- Pearson. Wechsler Adult Intelligence Scale, Fifth Edition (WAIS-5), product page and FAQ, checked 30 September 2026. www.pearsonassessments.com
The full picture
Your memory is one piece. Now see the whole picture.
Each game looks at one skill. The IQ test brings speed, reasoning and memory together in one score, with your percentile and a certificate.