Number Memory Test

A number memory test where you choose the digit count and display time and practice as many times as you like. Once the number disappears, type what you saw.

How this test works

Pick a digit count (3-15) and a display time (0.5-5s) with the sliders, then press Start. A random number shows for exactly the time you chose. Once it disappears, type what you saw and check your answer.

How this differs from FLASH: FLASH is a speed game where the display time automatically shrinks as you go. This tool keeps digits and time fixed at whatever you pick, so you can practice the same setting over and over at your own pace.

How to get better

• Instead of reading digit by digit, group them into chunks of 2-3 — it's easier to hold onto a few chunks than many single digits
• Turning digits into a story, rhyme, or familiar pattern (like a date) makes them stick
• Start at a digit count you can clear comfortably, then add one digit at a time as you succeed to push your best

Want to measure rapid recognition or reaction too?

Try FLASH, which automatically increases in difficulty, or our reaction time test. MIKIRI has fifteen free games — visual search (MATCH), eye tracking (FOLLOW) — each with a global top-100 leaderboard.

Try other tests

There is a firm limit on how many digits you can hold

The amount you can hold in mind at once is limited. The famous figure used to be "seven plus or minus two", but later work suggests that without grouping, the number of items people hold is smaller — around four.

Try it and you will feel it: past about seven digits it suddenly gets hard, and past ten you are no longer "remembering" so much as switching to a different method. That is not a lack of training; it is a structural limit everyone has.

People who go well beyond it are not expanding their capacity. They are changing how they group the digits (chunking).

Chunking methods that actually add digits

• Split into twos or threes — read 839217 as "839 / 217". Use the same split every time.
• Attach to numbers you already know — years, times, familiar codes. A chunk that already means something costs about as much as one item.
• Say it to yourself — repeating it as sound keeps it alive for the few seconds before you type.
• Don't move your eyes — with short display times there is no time to scan; take the whole number in at once.

These strategies work inside this task. Don't expect them to reduce everyday forgetfulness.

Change the display time and you measure something else

This tool lets you set both the number of digits and the display time. They are different kinds of difficulty, so change one at a time:

• More digits — tests how much you can hold.
• Shorter display — tests how fast you can take it in. Below about 0.1 seconds you stop reading and start catching an image.

Make both harder at once and you can't tell which one made you fail. That is why MIKIRI's FLASH only ever makes one of the two harder per level. Where players actually stop in FLASH is shown on the statistics page.

FAQ

What's a normal number of digits to remember?

Short-term memory is often estimated around 7 digits (the classic "magic number seven"), though techniques like chunking can push some people well past 10.

Does a longer display time make it easier?

Yes — a longer display leans more toward "careful study" than pure snapshot memory. If you want to test instant recall, set a short display time.

Which is the more serious memory test, this or FLASH?

Both are casual measurement tools. FLASH blends rapid-vision and speed pressure; this test isolates pure memory practice at settings you control.

Is this test free?

Completely free, no signup. Works in any phone or desktop browser.

This is a fun measurement tool, not a medical memory assessment.

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