Number memory test

Digits appear one per second. After the last digit, please type them in the same order. The test starts at 3 digits, adds one digit after each correct answer and ends after two wrong answers at the same length. Miller (1956) noted that people can recall about seven digits.

Starts at 3 digits

After you select “Start”, digits appear one at a time, one per second. After the last digit, please type them in the same order.

Result

Your longest correct number and the record of each try will appear here when the test ends.

Your results are calculated and saved only in this browser. They are not uploaded to our server. Select “Reset” to clear them.

Method and sources of error

  1. The test starts at 3 digits. The digits of each number appear one at a time, each shown for 0.7 seconds with a 0.3-second gap, that is, one digit per second. You type the number after the last digit.
  2. A correct answer adds one digit to the next number. A wrong answer gives one more try at the same length. Two wrong answers at the same length end the test. The longest number is 20 digits.
  3. Your result is the longest number you typed correctly (forward digit span).
  4. The digits are chosen at random in your browser. The same digit never appears twice in a row.
  5. Sources of error: the digits are shown on a screen, not read aloud. Attention, tiredness and memory methods, such as grouping digits in threes, all affect the result. This is not a medical test and cannot be used to assess memory disorders or cognitive conditions.

Sources

  1. Miller, G. A. (Psychological Review, 1956): The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information

Last checked: 31 October 2026.