<datalist>
Native autocomplete suggestions for an input — suggestions, not restrictions.
Baseline: Widely available · Forms
When to use it
Link it from an input's list attribute; users can pick a suggestion or type anything else.
When not to
If the value must come from the set, that's a select, not a datalist.
Key attributes
id- referenced by input list='…'
Example
<label for='topic'>Favorite element</label>
<input type='text' id='topic' name='topic' list='elements'>
<datalist id='elements'>
<option value='hgroup'></option>
<option value='output'></option>
</datalist>