use UI

Combobox vs Select

The deciding factor is not how the control looks but how many options there are and whether the user already knows them. A select is a closed, short, known list: pick one of these. A combobox is for when the list is too long to scan, so typing narrows it — and sometimes for when the answer might not be in the list at all. There is a second consideration people skip: on a phone, the native select opens the platform's own picker, and nothing you build competes with that for one-handed use. So the honest order is native select first, combobox when the list defeats it, and radios when there are only a handful and showing them all is cheaper than hiding them.

Short known list, use a select. Long enough that scanning fails, use a combobox — the moment someone wants to type, the decision is already made.

Combobox

An input paired with a list of options that narrows as the user types, used to pick one or more values.

Reach for it when

  • There are more options than a plain select can present comfortably — roughly a dozen and up.
  • The user usually knows what they are looking for, so typing three letters beats scrolling.
  • The list is long but finite and known: countries, currencies, repositories, teammates.
  • You need to pick several values and want them shown as removable chips.

Avoid it when

  • There are two to five options. Radios or a plain select show everything at once and need no typing.
  • Any text is valid. That is a plain input; forcing a match on free text only frustrates people.
  • The user does not know the vocabulary. If they cannot guess a word to type, filtering helps nobody — show a browsable list instead.
  • The choice triggers an action rather than setting a value. That is a command palette or a menu.

Select

A form control that shows the current choice and reveals a list of options to change it.

Reach for it when

  • There are roughly 3 to 15 options and the user knows them by sight — country, currency, status.
  • The list is fixed. Nothing the user types could add to it.
  • The field is one value in a form and the form owns the result.

Avoid it when

  • The list is long. Scrolling 200 countries to find Portugal is worse than typing three letters — that is a combobox.
  • There are two or three options and they all fit on screen. Radio buttons show every choice at once and cost one click instead of two.
  • The user might need something not in the list. A select cannot express “other”, and bolting a text field onto it is a combobox wearing a disguise.