GAME TOOL / 15
Number Memory
A string of digits shows for a few seconds, then disappears — type it back from memory. Every correct answer adds a digit; one wrong answer ends the run. Your score is the longest string you recalled.
HOW TO PLAY
- 1Watch the number while it's on screen
- 2When it hides, type it back and hit enter
- 3Right = one more digit, wrong = final score
No sign-up · runs entirely in your browser · scores stay on this device
Paused
Auto-paused in the background
Resume to keep playing.
Result
New device record!The card image is generated on your device and never uploaded; scores stay in this browser.
About this game
Number Memory measures raw short-term capacity — no chunking hints, no patterns, just how many digits survive one look. Strings are handled as text end to end, so 30+ digit runs never hit integer precision limits.
Longer strings get more display time (about +0.65s per extra digit, capped at 9s). Keyboard input and Enter both work; leaving the tab regenerates a fresh number of the same length so pausing can't be used to memorize.
How scoring works
- Score = the longest digit string answered correctly — higher is better.
- Digits are generated and compared as strings, so precision never degrades.
- Display time starts near 1.2s and grows ~0.65s per digit, capped at 9s.
- Most people hold 7–9 digits; past 12 is an unusually strong span.
Frequently asked questions
How does it work?
A digit string shows briefly, then hides — type it back and hit Enter. A correct answer adds a digit for the next level; a wrong one ends the run. Your score is the longest string you recalled.
Do the numbers keep getting longer?
Yes — one digit longer every level, with no cap. Digits are generated and compared as strings, so 30+ digit runs never hit integer precision limits. Display time grows about 0.65s per extra digit, capped at 9 seconds.
Anything to know about typing the answer?
Keyboard input and Enter both work, or use the submit button. Only digits are judged — stray spaces are ignored, but the digits themselves must match exactly.
What if I switch away mid-round?
The game pauses and covers the number. Resuming deals a fresh number of the same length — the original is gone, so pausing can't be used to memorize.
Where is my record kept?
Only in this device's browser — nothing is uploaded, no account, no global ranking. One tap on the result screen clears it.
How many digits is impressive?
The typical short-term span is 7–9 digits; past 12 is exceptional. Chunking digits into familiar groups — dates, area codes — helps a lot.