Corsi Block-Tapping test online: spatial span

How it works

A 2-block practice comes first and is not scored, then 2 rounds on the same board. You answer at your own pace, so the length depends on how far you get: about 7 minutes.

1 · Each sequence
Watch the blocks
Blocks light up one at a time, 0.8 seconds each with a short pause between them. Then the board waits for your answer.
2 · Round 1
Same order
Tap the blocks in the order they lit, then press Submit. Clear wipes your answer if you want to enter it again.
3 · Round 2
Reverse order
New sequences on the same board. This time you start with the last block that lit and work back to the first.
4 · Both rounds
One block longer
Sequences start at 2 blocks and grow to 9, with 2 tries at each length. Miss both tries at a length and that round ends.

Each tap marks the block with its place in your answer, and a counter shows how many blocks you have entered. Submit stays locked until you have tapped as many blocks as lit. During the rounds nothing tells you whether an answer was right.

Philip Corsi devised the board for his 1972 doctoral thesis at McGill University: 9 black cubes fixed to a board, tapped in sequence by an examiner while the person watched. It was built as the spatial partner of digit span. This version keeps the 9 blocks, their scattered layout and both directions, with lights in place of the examiner's finger.

What it measures

Both rounds ask you to hold a short route of places in mind and play it back. The reverse round makes you rework that route before you answer.

Round 1: same order

Visuospatial short-term memory: how many locations you can keep in sequence for a few seconds.
Serial order: remembering which block came when, not only which blocks lit.
Steady attention on the board while each sequence plays.

Round 2: reverse order

The same spatial storage, on fresh sequences.
Working on the sequence as well as holding it, because you replay it from the end.
Executive control, which dual-task studies find in the forward round too, not only in the reverse one.

Corsi is the spatial companion to digit span, which uses numbers. The two lean on partly separate memory stores, so one person can do better on locations and another on numbers. That is why clinicians often read them side by side.

In digit span, most people score lower backwards than forwards. In Corsi the two rounds are often about equally hard (Kessels et al., 2008), and dual-task work suggests both directions lean on executive control to a similar degree (Vandierendonck et al., 2004).

A test, not a diagnosis.

A span is a snapshot of one session on one task. On its own it cannot confirm or exclude a diagnosis.

What you get

Your spans appear on screen the moment the reverse round is over.

On the result screen

Your forward span and your backward span: the longest sequence you repeated correctly in each round.
A short reading of each span against broad adult ranges, about 5 to 6 blocks forward and 4 to 5 backward. These ranges are the same at every age.
An overall reading from your total span, forward plus backward.
A data panel with your correct sequences per round and the total.

When you keep it

A free account stores both spans, and you can come back to them from any device.
Listed under working memory in your results, next to Digit Span and the other memory tests you take.
A next test is offered as soon as you finish, so the picture of your thinking fills in.

How this version is scored

Every sequence shown, your taps and whether they matched are recorded. The spans come from that record.

Correct answer: Your taps match the sequence exactly: the same blocks in the same order, or in the exact reverse order in round 2. There is no partial credit and no time limit on your answer.
Span: The longest sequence length you got right at least once in a round, up to 9. Forward span and backward span are scored separately.
Stop rule: Both tries at a length always run. If you miss both, the round stops there and the next part begins. This is the rule of the standardised version by Kessels et al. (2000).
Total span: Forward span plus backward span, from 0 to 18. The overall reading uses fixed bands: 10 or more, 6 to 9, and below 6.
Correct sequences: How many sequences you repeated exactly, out of those shown, listed per round in the data panel. The practice sequence does not count.

Why speed does not count. Each block stays lit for a fixed time, but your answer is not timed. Corsi asks how much you can hold, not how fast you tap.

A fresh set every time. Sequences are drawn at random on each attempt, and a block can light more than once in a sequence, though never twice in a row. Standardised versions use fixed lists of sequences, so no two attempts here are identical.

No product score. Some studies also multiply span by the number of correct sequences to get a total score (Kessels et al., 2000). This version reports span and correct sequences separately and does not compute that product.

Reference values

Published averages for the physical board with an examiner, from 246 healthy adults aged 50 to 92 (Kessels et al., 2008). That study gave 2 sequences per length, as this version does.

Mean span length in blocks
Age	People	Forward	Backward
50 to 59	37	5.3	5.5
60 to 69	112	5.0	5.1
70 to 79	81	5.2	4.9
80+	16	4.8	4.6

The sample starts at 50. Kessels and colleagues collected it because adult norms for the backward round did not exist yet. Spans tend to be longer in younger adults.

Not directly comparable. These spans come from a physical board, with an examiner tapping fixed lists of sequences. Here the blocks light up on a screen, the sequences are random, you answer by tap or click, and the backward round can reach 9 blocks rather than 8. Each difference can shift a span.

The result screen does not turn your spans into a percentile against this table. Its reading uses the fixed ranges described above.

Before you start

A few quiet minutes make your spans easier to trust.

For a cleaner attempt

On a phone, set it down or hold it steady so the board does not move.
On a computer, make the window large enough to see all 9 blocks at once.
Silence notifications and stay on the tab until both rounds are done.
Keep your eyes on the board while it plays: a glance away can cost a block.

Interpret cautiously when

You were tired, in pain, hurried or interrupted during the rounds.
You rely on a screen reader, have low vision or use motor-access tools, which change what the score means.
You named or pointed at the positions as they lit, which turns part of the task into a verbal or motor one.
You took this test recently; a familiar task often goes a little better the second time.

Questions

What does the Corsi block test measure?

It measures visuospatial working memory: how many locations you can hold, in order, for a few seconds. The forward round is mostly storage. The reverse round also asks you to rework the sequence before you answer. Corsi is often paired with digit span, its counterpart for numbers.

What is a normal Corsi span?

There is no single cut-off. In a 2008 study of 246 healthy adults aged 50 to 92, average forward span went from 5.3 blocks at ages 50 to 59 to 4.8 from age 80, with backward span close to it, and younger adults tend to reach longer spans. Those values come from a physical board with an examiner, so treat them as context for a tapped, on-screen version. Your result screen reads your spans against fixed ranges, not age norms.

Can I take the Corsi test on my phone?

Yes. The board fits a phone screen and the blocks are large enough to tap. Set the phone on a table or hold it still, and keep the whole board in view while each sequence plays.

Why is my backward span close to my forward span?

That is common in Corsi. In the same 2008 study, about as many people did better backwards as forwards, while on digit span 84% did better forwards. One explanation is that both directions only ask you to recall the order of places that are already in front of you. One attempt is too little to read much into a gap either way.

Sources

By Cristian Dominguez Rein-Loring, Creative Technology Lead · Updated October 10, 2026

Start the Corsi test

When the reverse round ends you see both spans and can keep them with a free account.