· Memory · Original
Number Span: free digit span memory test, forwards and backwards
A string of digits flashes, one by one. Type it back, then backwards. Each round adds a digit: how long can you go?
What is Number Span?
Digits flash one at a time. Type them back in order, then backwards. Clear both and the next string is one digit longer. The classic digit-span test of working memory, as a game.
Number Span is a free working memory game based on the digit span test. Digits flash on the screen one at a time. Type them back in the same order, then type the same string backwards. Clear both and the next string gets one digit longer.
Forwards measures how much you can hold; backwards adds a mental operation on top, which is why it's harder. Most adults hold about seven digits forwards and five or six backwards. Your score is the longest string you cleared both ways.
The game uses the two classic versions of the task. Forward span asks you to hold a sequence; backward span asks you to hold it and turn it around at the same time, which leans on attention and mental manipulation as much as on raw storage. Seeing both scores side by side shows where your limit really is.
At a glance
- Category
- Memory
- Difficulty
- Medium
- Play time
- 2–3 min
- Price
- Free, in your browser, sign-up optional
How to play
- Watch
- Digits flash one by one, starting with three.
- Type
- Type them back in order, with your keyboard or the keypad.
- Reverse
- Then type the same digits backwards, last one first.
- Grow
- Both right: one more digit. A miss costs a life and shows the answer. Your score is your longest span.
Scoring
Your score is your longest span: the most digits you typed back right, both forwards and backwards.
A miss costs one of 3 lives and gives you a new string of the same length.
What it trains
- Working memory
- The classic digit-span task, forwards and backwards.
- Mental manipulation
- Reversing a sequence in your head, not just repeating it.
- Chunking
- Grouping digits to hold more of them.
Strategy and tips
- Chunk it
- Group digits in twos or threes, like a phone number: 4-8-1 becomes 481.
- Say them
- Repeat the digits silently as they flash. The inner voice is a memory buffer.
- Backwards from chunks
- Reverse each chunk, then the order of chunks.
- Stay calm on misses
- A miss gives a new string of the same length, not a reset.
- Short sessions
- A few runs a day beat one long session.
Why play Number Span?
Working memory is the notepad your brain uses to follow a conversation, do mental maths or remember a code for a few seconds. The digit span task is one of the oldest ways to stretch it.
It is also a quick, honest way to notice your own state: tiredness, noise and stress shrink your span in a way you can feel. Many players use a round as a two-minute focus check before studying or a meeting.
Frequently asked questions
Is Number Span free?
Yes. It is free and runs in your browser, with no download. Signing up is optional.
What's a good score?
Most adults clear 5 to 7 digits both ways. Past 8 is excellent.
Is it a medical test?
No. It's a game inspired by the digit span task; it doesn't diagnose anything.
Can I play on a phone?
Yes, with the on-screen keypad.
Why is backwards harder?
Backwards adds a task on top of remembering: you have to reorder the digits while still holding them, so most people score one or two digits less.
Does practice really raise my span?
Practice makes you better at this task, mostly through strategies like chunking. Those strategies help with phone numbers and codes too; the game makes no wider claim.