A sequence of digits will flash on screen. Memorize them, then type them back. Each correct round adds one more digit. The average is 7 digits.
Press Start to begin. You'll see a number, memorize it, then type it back.
Working memory is your brain's ability to hold and manipulate information in the short term. George Miller's famous research found that the average human can hold 7 ยฑ 2 items in working memory at once - known as "Miller's Law." People who score 9+ digits are in a small elite. Working memory span is arguably the most important human benchmark for general cognitive ability.
Working memory is strongly correlated with general intelligence and academic performance. Complement this test with the Reaction Time Test for a full cognitive speed profile, and check your Dashboard for trends.
Working memory span is arguably the most important human benchmark for predicting cognitive performance โ and it's one you can actually train with daily practice.
Number Memory tests your verbal working memory span - how many digits you can hold in short-term memory and accurately recall in order. It directly mirrors the Digit Span Forward subtest of the Wechsler Adult Intelligence Scale (WAIS-IV), one of the world's most widely used IQ batteries. George Miller's landmark 1956 paper "The Magical Number Seven, Plus or Minus Two" established that human working memory holds 7 ยฑ 2 items - and our test data consistently confirms this with a global average of 7 digits.
Working memory is not merely a trivia measure - it predicts academic performance, fluid intelligence, reading comprehension, and the ability to follow multi-step instructions. Individuals with higher digit spans tend to perform better on standardized tests, learn new languages more easily, and process complex information with less cognitive fatigue.
Working memory capacity itself is difficult to expand, but chunking - grouping individual digits into meaningful units - effectively multiplies your usable span. A phone number like 9821045678 becomes three chunks (982 / 1045 / 678) rather than ten individual digits. Memory champions use elaborate chunking systems to recall hundreds of digits, but even basic grouping can push a 7-digit span to apparent 10-digit performance.
For a related test using spatial rather than verbal memory, try the Corsi Block Test. Most people find their verbal span slightly exceeds their spatial span - a consistent finding across thousands of studies. The Digit Span Test adds a backward condition, which is even more diagnostic of working memory capacity.
7 digits is the global average. 8-9 digits puts you in the top 25%, and recalling 10 or more digits is exceptional, placing you in the top 5% of test takers.
This follows George Miller's landmark 1956 finding that human working memory holds 7 plus or minus 2 items at once, a limit set by how many distinct chunks of information the brain's short-term storage can maintain simultaneously.
Chunking is the most effective technique - grouping digits into meaningful units (like a phone number's area code) rather than trying to hold each digit separately, which can push apparent performance from 7 to 10 digits.
No, it measures one specific component - working memory span - which correlates with but is not equivalent to overall IQ, which spans multiple reasoning domains.
Number Memory typically only tests forward recall, while Digit Span often includes a backward recall condition too, which is a more demanding and diagnostic measure of working memory.
Working memory capacity, including digit recall, tends to gradually decline with age, though the decline is often gradual and varies significantly between individuals.
Yes, retaking the test allows you to practice chunking strategies, which can meaningfully improve your apparent digit span even without a true increase in raw memory capacity.
Memory competition athletes using advanced techniques have memorized well over 100 digits in controlled settings, far beyond the natural 7ยฑ2 span most people achieve without training.
Yes, both poor sleep and high stress can reduce working memory capacity temporarily, often producing a lower digit span than someone's typical baseline performance.
It correlates with fluid intelligence and academic performance because it mirrors the Digit Span Forward subtest used in the WAIS-IV, a widely used clinical IQ battery, though it measures only one narrow slice of overall cognitive ability.