Use a single select to have users filter options from a long list and select only one. A single select is especially appropriate when the list of available options is very long or when the space is limited.
List options in alphanumerical order unless a more suited ordering rationale applies, for example when listing size or security level options.
Always include the ability to filter options when the list contains 20 or more.
Keep titles and labels short, preferably under three words.
The title should indicate the type of information to provide.
Provide a descriptive title without action verbs. For instance, write "Favorite drink" rather than "Select your favorite drink".
Labels identify each option and should be self-explanatory. The width of the input should fully display the name of the selected option.
Use a consistent writing style for all options in the list.
The placeholder text should indicate the type of information to select. Use an action verb. For example, write "Select a drink" rather than "Select an option".
Allow the addition of custom values only when it doesn't increase the risk of failure and when there may be options other than those listed.
If your use case doesn't match the guidelines above, consider using one of the following components instead: