Symbol Coding test online: digit symbol substitution

A key pairs the digits 1 to 9 with 9 simple symbols. A digit appears, you tap its symbol, and the next digit follows at once. Your score is how many you match correctly in 90 seconds.

Start Symbol Coding

90 seconds timed · about 3 min · mouse or touch

When the 90 seconds are up you see your count and can keep it with a free account.

1 2 3 4 5 6 7 8 9 3
3 is the triangle: tap itTimed run · 90 seconds

How it works

10 practice items come first, without a clock, then one timed run of 90 seconds. With the instructions and a short countdown it takes about 3 minutes.

  1. 1 · Before the clock

    10 practice items

    Each practice answer gets a mark for 1 second: a tick if it matched, or the correct pair if it did not. Practice is not scored.

  2. 2 · Every item

    Look the digit up

    The key stays at the top of the screen the whole time, digits 1 to 9 each above its symbol. One large digit sits under it.

  3. 3 · Every item

    Tap its symbol

    Below the digit are 9 buttons, one per symbol. Their order is reshuffled on every item, so you have to find the symbol rather than count positions.

  4. 4 · Timed run

    90 seconds

    After a 3-second countdown the clock starts. A bar shrinks as time runs out, and items keep coming until it is empty.

Each tap moves you straight to the next item, with a brief colour flash that shows whether it matched. You cannot go back, and a wrong tap is counted as an error rather than stopping you. Answers are taps or clicks only; the keyboard is not used.

Digit symbol coding began more than a century ago as a laboratory tool for studying how people learn associations. Its clinical use took hold in the 1940s, and today it is among the most widely used tests in neuropsychology (Jaeger, 2018). Paper versions ask you to write symbols under long rows of digits. Here you see one digit at a time and tap its symbol instead.

What it measures

Each item is a small loop: find the digit in the key, read its symbol, spot that symbol in the answer row and tap it. The score counts how many loops you complete in 90 seconds.

Speed

  • Processing speed: how quickly you carry out a simple step again and again.
  • Visual scanning: moving your eyes between the key, the digit and the answer row.
  • Motor speed: reaching the right button and tapping it, item after item.

Accuracy and effort

  • Holding the right pairing in mind for a moment while you search the row.
  • Sustained effort: keeping your pace from the first item to the last.
  • Accuracy, reported as the share of your taps that matched.

Speed tests sit near the centre of many test batteries. Salthouse (1996) built a theory of how thinking changes across adulthood around processing speed, and coding tasks are among the most common ways to measure it.

Jaeger (2018) describes the test as sensitive rather than specific: many different things can lower a count, from tiredness to illness to an unfamiliar device. A low count tells you that something slowed the work down, not what it was.

Counts also differ with background. In a 2024 study of Hispanic and Latino adults in the United States, age, education, sex, heritage and language preference were all linked to scores (Morlett Paredes et al., 2024). Spanish norms for the related Symbol Digit Modalities Test found that education affected scores in young adults as well (Tamayo et al., 2012).

A test, not a diagnosis.

A count from one 90-second run describes that run. On its own it cannot confirm or rule out a diagnosis.

What you get

Your count appears as soon as the 90 seconds end.

On the result screen

  • Your number of correct items in 90 seconds, in large type.
  • A one-line reading from fixed cut-offs: 55 or more, 35 to 54, or under 35. A note adds that adults aged 20 to 60 often score 35 to 65. The cut-offs do not change with age.
  • A bar from lower to higher with a shaded middle band and a marker for your count.
  • Accuracy, your average time per correct item in milliseconds, and how many items you attempted.
  • A data panel with correct items, errors and both average times, plus a CSV file of every item.

When you keep it

  • Save the count with a free account and open it again from any device.
  • It is filed under processing speed in your results, next to Reaction Time once you take it.
  • Another test is suggested when you finish, so your results reach beyond a single area.

How this version is scored

Every item records the digit, the symbol you tapped, whether it matched and how long you took. The result screen is built from that record.

Correct
A tap on the symbol the key pairs with the digit on screen. Only the timed run counts; the 10 practice items do not.
Errors
A tap on any other symbol. Errors are listed separately and do not subtract from your correct count.
Accuracy
Correct items divided by items attempted, as a whole percentage.
Average time
The mean time from an item appearing to your tap, in milliseconds. The screen leads with the mean over correct items; the data panel also gives the mean over all items.
Time limit
90 seconds from the end of the countdown. An item still on screen when time runs out is dropped, not scored.

Why the answer row moves. If the buttons followed the key order, you could tap by position and skip the lookup. Here the 9 buttons are reshuffled on every item, so each answer needs the key.

Tapping is not writing. Paper versions ask you to draw each symbol, often for a different length of time, and published norms come from those versions. Finding and tapping a button is a different movement, so counts from this version are not directly comparable. The result screen does not turn your count into a percentile.

A new sequence every time. Digits are drawn at random for each attempt, and the same digit can come up twice in a row. No two runs show the same list.

Before you start

The score is a count against the clock, so small things in your setup show up in it.

For a cleaner attempt

  • Use the device you handle most easily; on a phone, rest it on a table or hold it steady.
  • Check that the key and all 9 buttons fit on screen without scrolling.
  • Silence notifications: 90 seconds is short, and one interruption costs several items.
  • Use the practice to learn where the symbols sit, not to race.

Interpret cautiously when

  • You were tired, unwell or distracted, or had to stop during the run.
  • You have low vision, a tremor or use assistive input, which slow tapping for reasons that have nothing to do with thinking speed.
  • You used a small screen, where the buttons sit close together and are easier to miss.
  • You have done this test before; the pairs get familiar and counts tend to rise.

Questions

What does the digit symbol substitution test measure?

Mainly processing speed: how fast you carry out one simple step over and over. Each item also needs visual scanning between the key and the answers, a quick hand movement, and enough attention to hold the right pair while you search. It is short and sensitive to many kinds of change, and for the same reason one score does not point to a single cause.

What is a good score on Symbol Coding?

There is no single cut-off. The result screen reads 55 or more correct in 90 seconds as strong and under 35 as below its range, and it notes that younger adults tend to score higher. Paper norms count written symbols, often over a longer time, so they do not carry over to a tapped version. Comparing your own attempts under similar conditions tells you more.

Can I take the Symbol Coding test on my phone?

Yes. The key and the 9 answer buttons fit a phone screen and work by touch. A larger screen leaves more room between buttons, so if you want to compare attempts, use the same device each time.

Is this the same as the Symbol Digit Modalities Test?

They are close relatives. Both pair digits with symbols through a key. In the digit symbol substitution format you see a digit and give its symbol; in the Symbol Digit Modalities Test you see a symbol and give its digit, in writing or aloud. This version follows the first format, with taps in place of writing.

Sources

By Cristian Dominguez Rein-Loring, Creative Technology Lead · Updated October 12, 2026