Is it possible to change font size of the search box in Bootstrap select?
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<select class="selectpicker" data-live-search="true">
<option>Option 1</option>
<option>Option 2</option>
</select>
Bootstrap-Select generates some HTML for you, so the thing you want is to inspect the HTML and then write some CSS to override the attributes given by the library.
CSS:
This should work for you. Hope this answers your question.