Digit Span Test — Free Number Memory Span Check

Digits are drawn at random from 0 to 9, and the same digit never appears twice in a row. Each digit stays on screen for 0.8 seconds, followed by a 0.4-second blank, so one digit passes every 1.2 seconds. Then a number pad appears; your answer is scored the moment you enter the last digit, so fix any slip with Delete before that. You start at 3 digits and gain 1 digit per success; after a miss you get one more try at the same length with a fresh sequence. The test ends after 2 misses at the same length, or once you get 10 digits right.

The top of the result screen shows the longest sequence you recalled correctly and your total number of attempts. The detailed report adds your correct and wrong counts, accuracy, your span as a share of the 10-digit maximum, and one line per attempt showing its length and whether you got it right. That lets you tell a clean 7 apart from a 7 reached after one miss. The short interpretation uses three bands: 9 digits or more, 5–8, and 4 or fewer. Because the test stops at 10 digits, if you clear 10 your real span may be longer still.

In the working memory model of Baddeley and Hitch (1974), digits are held in the ‘phonological loop’, which stores sound-based information briefly and keeps it alive through silent rehearsal. Baddeley, Thomson and Buchanan (1975) showed that shorter words are recalled better and that span can be predicted from how many words a person can read in about 2 seconds — so span is tied to rehearsal time, not only to the number of items. Cowan (2001), reviewing studies in which rehearsal and chunking were prevented, concluded that people hold about 3 to 5 chunks at once, around 4 on average.

So the familiar span of around 7 digits is better seen as a short-lived store plus silent rehearsal and grouping, rather than one pure capacity. This test uses forward recall only: you enter the digits in the order shown. A review of order recall notes that with verbal material, performance is usually worse when the sequence must be recalled backward (Donolato et al., 2017); reversing the order adds a manipulation step, which moves the task from holding information toward working with it. If you want to try backward recall too, it is part of the working memory section in Cognitive ability (IQ).

Even when digits are shown on screen, most people silently read them and hold them as sounds. Conrad (1964) found that when visually presented letters were recalled, errors systematically involved letters that sound alike. That is why the time it takes to say digit names matters. Ellis and Hennelly (1980) reported that Welsh–English bilinguals had shorter digit spans in Welsh, whose digit names are longer, and Stigler, Lee and Stevenson (1986) found that Chinese-speaking children, whose digit names are pronounced quickly, remembered more digits than English-speaking children.

Compare your results with your own earlier runs in the same language, not with people who rehearse digits in another. The format differs too: in the Wechsler digit span subtest used in clinics, an examiner reads the digits aloud at 1 per second and you answer out loud, whereas here one digit appears on screen every 1.2 seconds and you type. Hearing a list tends to boost recall of its last items — the modality effect (Crowder and Morton, 1969) — so the two scores are not interchangeable. Use this score as a yardstick against your own records taken the same way, not as a stand-in for a clinical score.