How long does each number stay on screen?

One second plus half a second for each digit, timed from the moment it is drawn. Three digits stay up for two and a half seconds, ten digits for six.

How is my score worked out?

It is the length of the longest number you typed back exactly. Round 1 has three digits and each round adds one. If you get the 8-digit number right and miss the 9-digit one, your score is 8. A miss in round 1 scores 0.

Is it cheating to split the number into groups?

No. Grouping digits into chunks is one of the main ways memory copes with long numbers, and it is how most people remember phone numbers. The test doesn't try to stop it.

You can fix the answer before you press Enter. Once it is submitted it counts. Spaces and any other characters that aren't digits are ignored.

Is this a medical test?

No. It is a game that shows how much your short-term memory holds on the day. It cannot diagnose anything, and tiredness or distraction will move your result.

Where are my results saved?

Only in this browser, in its local storage: the last 20 runs of each mode. Nothing is sent to HourLife, and clearing your browser's site data or pressing Clear removes them.

Games
Brain tests
Number Memory Test

Number memory test

A number shows for a moment, then hides. Type it back. It starts at three digits and grows by one each round, until one gets away.

Play full screen Your results

Starts at 3 digits one more each round
Any keyboard the number pad opens on phones
No account your scores stay in this browser

Only the display is timed, so your device makes little difference. On a phone, the number pad opens when the answer box appears.

Your results

No runs yet. Take the test above and your scores appear here.

Kept in this browser only: your last 20 runs of each mode. Nothing is sent to HourLife.

How it works

Read the number
Press Play and then Start. A number appears in large digits for one second plus half a second per digit, so three digits stay up for two and a half seconds. A thin bar shrinks to show the time left.
Type it back
The number hides and an answer box appears. Type what you remember and press Enter or Submit. Spaces don't matter, so you can type it in groups.
Go until one slips
Right, and the next number is one digit longer. Wrong, and the run ends, with the number and your answer one above the other and the digits that differ underlined. Your score is the longest number you got right.

What a span of digits measures

This is a version of the digit-span task: take in a list of digits, then give it back in order. The longest list you can repeat is your span, and span tasks like it have long been used to study short-term memory.

In 1956 George Miller pointed out that, for many kinds of material, the span of immediate memory is about seven items, and that people stretch it by recoding: grouping small items into bigger chunks. Nelson Cowan later gathered the evidence that when grouping is blocked, the real limit is smaller, about three to five chunks.

That is why the way you read a number matters. Seeing 472916 as 472 and 916 turns six digits into two groups, and you're welcome to do it. It is a game, not a diagnosis, and your result moves with sleep, attention and noise around you.

Sources: Miller, The magical number seven, plus or minus two, Psychological Review 63(2) (1956); Cowan, The magical number 4 in short-term memory, Behavioral and Brain Sciences 24(1) (2001).

Questions

How long does each number stay on screen?

One second plus half a second for each digit, timed from the moment it is drawn. Three digits stay up for two and a half seconds, ten digits for six.
How is my score worked out?

It is the length of the longest number you typed back exactly. Round 1 has three digits and each round adds one. If you get the 8-digit number right and miss the 9-digit one, your score is 8. A miss in round 1 scores 0.
Is it cheating to split the number into groups?

No. Grouping digits into chunks is one of the main ways memory copes with long numbers, and it is how most people remember phone numbers. The test doesn't try to stop it.
What if I mistype?

You can fix the answer before you press Enter. Once it is submitted it counts. Spaces and any other characters that aren't digits are ignored.
Is this a medical test?

No. It is a game that shows how much your short-term memory holds on the day. It cannot diagnose anything, and tiredness or distraction will move your result.
Where are my results saved?

Only in this browser, in its local storage: the last 20 runs of each mode. Nothing is sent to HourLife, and clearing your browser's site data or pressing Clear removes them.