Digit Span Test
Digits appear one at a time, then you type them back. Get it right and the next sequence is one digit longer. A free online digit span test — forward or backward, 3 digits to start, no account, everything generated and scored in your browser. Where you stop is your span.
Take the test
Digits appear one at a time. Type them back in the same order.
Digits appear one at a time. Type them back in reverse order.
Correct. The next sequence is one digit longer.
Correct — and 12 digits is the top of the ladder.
Not this time. The same length comes round again.
0
digits, your span
That is your span — the longest sequence that came back complete. Much of the movement between runs is attention rather than capacity, so a single number wanders more than you would expect.
No sequence came back complete this time. The first one is only 3 digits — worth another go, somewhere quieter.
- Span
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- Rounds
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- Ladder
- 3–12
Digits arrive at one digit a second — the rate the standard procedure uses. The keypad and the number keys both work. Nothing is uploaded; your span stays in this tab.
That was a single run. In the app it becomes a short daily session, with a Focus Index to show for it.
Point your camera at the code — the App Store opens.
What a digit span test measures
Your verbal span — how long a list of items you can hold intact for the few seconds between seeing it and giving it back. Strictly, the forward mode measures short-term storage and the backward mode is the one that earns the name working memory; the task is filed under working memory because that is where the batteries put it. Not how well you remember your childhood, and not how quickly you think: how much order survives the gap.
The task is deliberately thin. There is nothing to work out, nothing to know and nothing to be fast at; the only thing standing between you and a perfect run is the length of the list. That thinness is why it has lasted since 1887 and why it sits in clinical batteries next to far more elaborate subtests — a measure with almost no content is a measure with almost nothing else to confound it.
What it does not measure is capacity in the pure sense. Everyone rehearses: you say the digits under your breath, you group them in threes, you hear a phone number in them. All of that is allowed here, all of it raises a span, and it is the reason digit spans come out well above the roughly four items that studies find once rehearsal and grouping are blocked. A digit span is what your memory does with help, which is also how you use it.
Forward and backward are two different tasks
two modes, one instrument. The digits arrive the same way in both — the difference is entirely in what you do with them.
Forward asks you to hold a list and hand it back unchanged. It is close to a straight storage measure: the list goes in, the list comes out, and the only question is how long it can be.
Backward asks you to hold the list AND turn it around before you answer. That extra step loads the part of working memory that manipulates rather than stores — the standard reading of the difference, and the one the scales are built on, though it is not the only account on offer. Either way backward spans come out shorter: the two ranges quoted further down differ by two digits, and the studies behind them put the gap at a digit and a half. It is why every standard battery reports the two separately instead of averaging them.
They are modes rather than two pages here for the same reason: they share the stimulus, the ladder and the stopping rule, and only the instruction differs. Switching the mode resets the run, because a sequence shown under one instruction cannot honestly be answered under the other.
Where it comes from
- 1887
Jacobs measures the first span
Joseph Jacobs asks schoolchildren to repeat back strings of digits, one digit longer each round, and writes down where each child stops. The procedure — grow the list until it breaks, then call the last success the span — is still, in outline, how a span is measured, here included — though the modern scales total the trials passed and treat the longest span as a secondary figure.
- 1939
It becomes a standard subtest
David Wechsler puts digit span into the Wechsler-Bellevue scale, forward and backward in the same subtest, and it has survived every revision since. That is why the task is familiar to anyone who has sat a formal assessment — and why so many published figures exist for it.
- 1956
The most misquoted number in psychology
George Miller’s “The Magical Number Seven, Plus or Minus Two” argues that immediate recall is limited to about seven CHUNKS — not seven digits, and not a span score. The paper is about how items are grouped: Miller opens it complaining that he has been persecuted by an integer, and closes it calling the seven a Pythagorean coincidence.
- 2001
The estimate is revised down
Nelson Cowan reviews the tasks that block rehearsal and chunking and puts the real capacity closer to four items. Digit spans come out higher than that precisely because digits CAN be rehearsed and grouped — which is a fact about the task, not a contradiction.
- Today
Two spans, not one
Forward and backward span are still reported separately, because the backward version asks for something extra: the list has to be held AND turned around. That difference is the reason both modes exist on this page rather than one.
How the ladder works
The procedure is a staircase, and it is the oldest part of the test: grow the list until it breaks, then call the last success the span.
A run opens at 3 digits. Every sequence you reproduce in full makes the next one a digit longer. Every sequence you miss keeps the length where it is and spends one of your chances at it — and two errors at the same length end the run. One miss at a length is a slip; the second one is where the limit actually is, which is why a single error does not end the run and unlimited attempts are not offered either. Unlimited attempts would measure patience rather than recall.
The ceiling is 12 digits, which no run is expected to reach — it exists so that “grow until you fail” has a terminating case for a visitor who does not fail. With those rules a run cannot exceed 20 sequences however it goes, and typically ends in far fewer. The digits themselves are drawn so that no digit follows itself, no digit returns two places later, and no three in a row form a run like 4 5 6: a sequence that chunks is measuring whether you spotted the chunk, not how much you can hold.
Each digit is on screen for 700 ms with a 300 ms gap after it — one digit a second, which is the rate the standard procedure specifies for reading the list aloud. It is the one piece of our timing that follows a published convention rather than taste.
A worked example of a digit span run
One complete run, laid out round by round, so the procedure above can be read as well as played. Every digit below was drawn by the generator this page runs on, from a fixed seed — so this is a real run of the instrument rather than a picture of one, and it is the same run every time you load the page.
It is played in Forward mode: each sequence has to come back in the order it arrived. The ladder opens at 3 digits, as every run does.
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Round 1 3 digits Recalled
Shown 832
Typed back in full, so the ladder moves up: the next sequence is 4 digits.
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Round 2 4 digits Recalled
Shown 6319
Typed back in full, so the ladder moves up: the next sequence is 5 digits.
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Round 3 5 digits Recalled
Shown 32982
Typed back in full, so the ladder moves up: the next sequence is 6 digits.
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Round 4 6 digits Missed
Shown 296342
Typed 2 9 6 3 2 4
The last two digits came back in the wrong order. Nothing here is scored in halves, so the round is lost: the length stays at 6 and one of its two chances is spent.
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Round 5 6 digits Recalled
Shown 756437
Typed back in full, so the ladder moves up: the next sequence is 7 digits.
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Round 6 7 digits Missed
Shown 3817384
Typed 3 8 1 7 3 4 8
The last two digits came back in the wrong order. Nothing here is scored in halves, so the round is lost: the length stays at 7 and one of its two chances is spent.
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Round 7 7 digits Missed
Shown 1462718
Typed 1 4 6 2 7 8 1
A second miss at 7 digits — two errors at the same length end the run, and this one does.
The run ends with a span of 6 — the longest sequence that came back complete, and the only number this page reports. Read it for what it is: 6 digits held, and 7 missed twice directly above it. A span is the last rung that held, with a failure sitting on the next one; it is not a best-ever and it is not a score out of anything.
Backward mode changes exactly one thing about all of that. The same round one would have shown the same 3 digits — 8 3 2 — and asked for 2 3 8 instead. Same ladder, same stopping rule, same draws; only the instruction differs, which is why the two spans are tracked side by side and never averaged.
How to read your result
One number, and it is deliberately blunt.
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Your span
The longest sequence that came back complete, in the order the mode asked for. Partial credit does not exist here: one digit out of place is a failed round, because a sequence you nearly have is a sequence you do not have.
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Rounds
How many sequences you were shown, at most 20. A span reached in few rounds means you were not slipping on the way up; the same span after several misses is a shakier number.
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Which mode it came from
A forward span and a backward span are not the same quantity and must never be compared with each other. The card says which one you just played; the two are worth tracking side by side, not merged.
Digit span, n-back and Corsi
Three working-memory tests, three different questions. It is worth knowing which one you just answered.
The N-Back Test asks about updating rather than capacity: nothing sits still, every new letter forces the answer to be recomputed against one from n steps back, and the result is a pair of counts rather than a span. It is the harder and more famous task, and the one whose training claims have not held up.
The Corsi Block Test is this same ladder with the words taken out. Nothing on its board has a name, so the sequence has to be held as a path rather than as a list — and because people can be good at one and poor at the other, the pair is a large part of the evidence that verbal and visual-spatial working memory are separate systems. Corsi established it in 1972 as the nonverbal counterpart to digit span.
What this version cannot tell you
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A span is a coarse number
It moves in whole digits, so there is nothing between 6 and 7. Two runs differing by one are not meaningfully different, and the same person routinely lands a digit either side of where they were an hour ago.
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Rehearsing is part of the task
Saying the digits under your breath, grouping them in threes, hearing them as a phone number — all of it raises a span, and all of it is what everybody does. It is why digit spans sit well above the four-item estimate for capacity with rehearsal blocked.
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Our procedure is not the clinical one
The standard version is read aloud by an examiner and answered out loud. Here the digits are shown on a screen and typed back on a keypad, at one digit a second. That is a different instrument, so a number from this page does not map onto a published one.
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It is not a diagnosis or a score
Digit span sits inside professionally administered batteries, always beside other subtests and read by someone qualified. One task in a browser tab is not that, and nothing here turns your span into an IQ or into any other score.
Questions about the digit span test
What is a digit span test?
A sequence of digits is shown one at a time and you repeat it back. Get it right and the next sequence is one digit longer; two errors at the same length end the run. The last length you reproduced in full is your span. It is one of the oldest measures in the field — Joseph Jacobs ran it on schoolchildren in 1887 — and, in outline, the oldest still administered today more or less as it was written down.
What is a good digit span?
We publish no norms of our own, and anyone quoting a percentile for a browser test is guessing. What can honestly be said is what the literature reports: forward spans for healthy adults usually cluster around 6–7 digits and backward spans around 4–5, measured with an examiner reading the digits aloud at one a second. Our version is typed on a keypad from digits on a screen, which is a different procedure, so treat those figures as background rather than as a target you either hit or miss. The comparison that actually works is with your own earlier runs, in the same mode, on the same device.
What is the difference between forward and backward digit span?
Forward span asks you to hold a list and give it back unchanged. Backward span asks you to hold it AND turn it around before you answer — which, on the standard reading, loads the part of working memory that manipulates rather than merely stores. Backward spans do come out shorter: the ranges quoted on this page differ by two digits, and the studies behind them usually put the gap at a digit and a half. The two are reported separately in every standard battery. On this page they are two modes of the same instrument, and the switch resets the run: a sequence shown under one instruction cannot be answered under the other.
Why does the test end after two misses at the same length?
Because on a digit span ladder one miss at a length is a slip and two is a limit. A single error ends the run too early — attention wanders, a finger lands on the wrong key — and giving unlimited attempts would let anyone reach any length eventually, which would measure patience. The rule here is the classical one: two errors at the same length end the run, and it is written down once in the code the test runs on, so this sentence cannot drift from the behavior.
Is seven the normal digit span?
That number comes from George Miller’s 1956 paper, and it is not what the paper says. Miller argued that immediate recall holds about seven CHUNKS — groups of items, however large each group is — which is why a span of digits, a span of words and a span of unrelated syllables come out at very different lengths. Later work, in particular Nelson Cowan’s 2001 review of tasks that block rehearsal and grouping, puts the underlying capacity closer to four items. Digits come out higher because they are easy to rehearse and easy to group. So: seven is a famous number about chunks, not a pass mark for this page.
How does the digit span test compare with the n-back test?
They ask different questions. Digit span asks how much you can hold: the list sits still and only gets longer, so the answer is a capacity, a small whole number. The n-back never sits still — every new letter forces the answer to be recomputed against one from n steps back — so it loads updating rather than storage, and it reports hits and false alarms instead of a span. People who do well on one do not reliably do well on the other, which is exactly why both are worth taking.
How is it different from the Corsi block test?
Same ladder, different material. Digit span is verbal: the digits have names, so they can be rehearsed under your breath. The Corsi block test is spatial: nothing on the board has a name, so the sequence has to be held as a path. Philip Corsi’s 1972 thesis established the block task as the nonverbal counterpart to digit span — the board itself goes back to Knox’s cube test of 1913 — and the two spans can come out differently in the same person — which is a large part of the evidence that verbal and visual-spatial working memory are separate systems.
Is the digit span test used to screen for ADHD?
No, and a version in a browser tab least of all. Digit span does appear in assessments where attention and working memory are being looked at, but always inside a battery, administered under controlled conditions and interpreted by someone qualified alongside a history and an interview — and a short span on its own identifies no condition at all. Plenty of people with a small span have nothing whatever going on, and plenty of people with a long one do. If your concentration or your recall genuinely worries you, this page is not the place to find an answer; a clinician is.
Is this an IQ test?
No. Digit span is one subtest that appears inside IQ batteries, and one subtest is not a battery. This page reports what it actually measured — the longest sequence you typed back correctly, in the mode you chose — and nothing on it estimates an IQ, a percentile or a mental age. No single task in a browser tab honestly could.
Do I need an account?
No. The digit span test generates its sequences in your browser and scores them there too — nothing is uploaded, nothing is stored, and your span is gone when you close the tab. There is no email box anywhere on this page.
One evening’s span is a number. A month of them is a picture.
A span from one afternoon moves with how alert you happened to be. In NEURA the tasks adapt to you, run inside a daily session of 20, and roll up into a Focus Index you can watch move over weeks — the part a single ladder, climbed once, can never show you.
