Components

Combo box

Use with caution: Candidate English, Spanish

USWDS v3

A combo box helps users select an item from a large list of options.

Examples

Usage

Refer to the U.S. Web Design System for usage guidance

Choosing the right component for the task

Consider how many options the user will have when choosing the right component. The number of options will determine what component is right for the task.

2 - 5: Radio Buttons. Use radio buttons when there are only a few options that can all be exposed at once.
6 - 15: Select. Use a select for a limited number of options.
16 - 100: Combo Box. For over 15 items, use a combo box that combines a select with typeahead.
101 - ∞: Search Input typeahead. Over 100 items, use the search input component with typeahead.

Some exceptions when choosing the right component

Some exceptions can be considered when choosing the right component.

When the options are known and memorable. Use the combo box when the user will know what to expect as options in the dropdown. Some examples of this would be a list of countries or states. See the USWDS address pattern for an example.
When the radio button labels are long or radio tiles contain descriptive text. Using long labels within a dropdown might create an issue where the information needed to make a selection is lost. There’s also descriptive text added within radio tiles that can’t be used in a dropdown. In those use cases a radio button might be required instead of a dropdown opton.

These are some things to consider when choosing between different components. Contact the Design System team for help if you have other use cases that are considered exceptions.

Errors

Refer to the specific error example above.

View form error handling for additional guidance

Hint text

Refer to the hint text example above.

View label hint text for additional guidance

Code usage

Attributes and Properties

Property	Attribute	Type	Default	Description
`disabled`	`disabled`	`boolean`	`false`	The combo box component will be disabled / read-only.
`error`	`error`	`string`		Error message to display. When defined, this indicates an error.
`hint`	`hint`	`string`		Optional hint text.
`label`	`label`	`string`		Text label for the field.
`messageAriaDescribedby`	`message-aria-describedby`	`string`		An optional message that will be read by screen readers when the select is focused.
`name`	`name`	`string`		Name attribute for the select field.
`placeholder`	`placeholder`	`string`		The placeholder string.
`required`	`required`	`boolean`	`false`	Whether or not this is a required field.
`value`	`value`	`string`		Selected value (will get updated on select).

Events

Name	Description
`vaSelect`	The event emitted when the selected value changes

Accessibility considerations

Refer to the U.S. Web Design System for accessibility guidance

Component checklist

Maturity

Guidance: Examples, usage, code usage, content considerations, and accessibility considerations are all complete.
Research: VFS team conducted research on this component which is linked from this page.
Stability: Component has been in production for more than 3 months with no significant issues found.
Adoption: Multiple teams have adopted this component.

Accessibility

While this component has been previously tested against older criteria, it has not yet been audited with the updated testing criteria.

Code assets

Variations: Storybook includes all variations (style, size, orientation, optional iconography, selection, error state, etc.)
Responsive: Component depicted in all responsive breakpoints.
Interactive states: Includes all interactive states that are applicable (hover, active, focus, keyboard focus, disabled).
Tokens: All design attributes (color, typography, layout, etc.) are available as tokens.
Internationalization: Describes i18n attributes.

Visual assets

Variations: Sketch library includes all variations (style, size, orientation, optional iconography, selection, error state, etc.)
Responsive: Component designed to work in all responsive breakpoints.
Interactive states: Includes all interactive states that are applicable (hover, active, focus, keyboard focus, disabled).
Tokens: All design attributes (color, typography, layout, etc.) are available as tokens.

Combo box

Examples

Default

With Default Value

With Error

Required

With Placeholder Text

With Hint Text

With Message Aria Described By