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Slider

A numeric field entered by dragging a handle along a range rather than typing.

Where to find it

Architect Panel → Data:

  • Datastores — the datastore, then Table Designer to add or edit a field

What it stores

A number, exactly as a number field does. The difference is entirely in how it is entered — which means the choice is a usability decision, not a data one.

Where it works well

  • Bounded ratings — satisfaction, confidence, priority on a fixed scale.
  • Approximate values where precision is not the point.
  • Percentages, where the ends are meaningful and the middle is a judgement.
  • Touch interfaces, where dragging beats typing.

Where it does not

Anywhere the exact number matters. A slider makes entering a precise value harder than typing one — try setting 47 on a 0–100 slider on a phone — and users will accept whatever is near enough.

That is fine for a satisfaction rating and unacceptable for a price, a quantity or an age.

It biases the answer

Worth knowing if the value is data you will analyse. Sliders cluster: at the ends, at the middle, and at the position the handle starts in. Somebody who feels roughly positive drags to about three-quarters rather than deciding on 78.

So slider data is coarser than it looks, and treating a 73 as meaningfully different from a 76 is over-reading it.

Set the range and step deliberately

The range defines what is possible and the step defines how fine the choice is. A step of one on a 0–100 slider offers a hundred positions nobody can distinguish; a step of five or ten gives you honest data and an easier control.

Where you want a rating, consider whether five or ten discrete options — as radios or pills — would serve better and read more clearly in a report.

Mind the starting position

Wherever the handle starts is where an untouched field records a value. If it starts in the middle, every skipped question records a neutral answer that looks like a real one.

Decide whether an unanswered slider should be distinguishable from a deliberate middle, and if so do not default it to the middle.

Accessibility

Sliders are harder to operate for some users than a number box or a set of options, and harder still on a small screen. Where a field is on a public form, that matters more than the visual appeal.

Worked example

A feedback form uses a 0–10 slider with a step of one for likelihood to recommend, which is the conventional scale for that question. A separate "hours spent" field on the same form is a number box, because 3.5 hours needs to be exact and nobody should be dragging for it.

Recommendations

  • Use it for judgements, never for exact values.
  • Choose a coarse step — fine ones give false precision.
  • Think about the starting position and what an untouched field records.
  • Consider radios or pills for small rating scales.