Basic select boxes


<select class="form-control" id="sel1" name="sellist1">
   <option>1</option>
   <option>2</option>
   <option>3</option>
   <option>4</option>
</select>

Mutiple select


<select multiple class="form-control" id="sel2" name="sellist2">
   <option>1</option>
   <option>2</option>
   <option>3</option>
   <option>4</option>
   <option>5</option>
</select>

Basic Select with Input Group


<div class="input-group mb-3">
   <div class="input-group-prepend">
      <label class="input-group-text" for="inputGroupSelect01">Options</label>
   </div>
   <select class="form-control" id="inputGroupSelect01">
      <option selected="">Choose...</option>
      <option value="1">One</option>
      <option value="2">Two</option>
      <option value="3">Three</option>
   </select>
   </div>
   <div class="input-group">
   <select class="form-control" id="inputGroupSelect02">
      <option selected="">Choose...</option>
      <option value="1">One</option>
      <option value="2">Two</option>
      <option value="3">Three</option>
   </select>
   <div class="input-group-append">
      <label class="input-group-text" for="inputGroupSelect02">Options</label>
   </div>
</div>

Single Select2


<div class="form-group">
   <select class="form-control ">
      <option>Java</option>
      <option>Javascript</option>
      <option>PHP</option>
      <option>Visual Basic</option>
   </select>
</div>

Multiple Select2


<select id="multiple" class="js-states form-control" multiple>
   <option>Red</option>
   <option>Green</option>
   <option>Blue</option>
   <option>Yellow</option>
</select>

Custom Select


<select class="custom-select form-control">
   <option selected="">Open this menu</option>
   <option value="IT">IT</option>
   <option value="Blade Runner">Blade Runner</option>
   <option value="Thor Ragnarok">Thor Ragnarok</option>
</select>

Disabled Select


<select disabled="disabled" id="disabledSelect" class="form-control">
   <option>Disabled select</option>
   <option>1</option>
   <option>2</option>
   <option>3</option>
</select>

Custome Select with Input Group


<div class="input-group mb-3">
   <div class="input-group-prepend">
      <label class="input-group-text" for="inputGroupSelect03">Options</label>
   </div>
   <select class="custom-select" id="inputGroupSelect03">
      <option selected>Choose...</option>
      <option value="1">One</option>
      <option value="2">Two</option>
      <option value="3">Three</option>
   </select>
</div>

Custom Select Menu Sizing


<form>
   <select class="custom-select custom-select-sm mb-3">
      <option selected>Small Custom Select Menu</option>
      <option value="volvo">Volvo</option>
      <option value="fiat">Fiat</option>
      <option value="audi">Audi</option>
   </select>
   <select name="cars" class="custom-select mb-3">
      <option selected>Default Custom Select Menu</option>
      <option value="volvo">Volvo</option>
      <option value="fiat">Fiat</option>
      <option value="audi">Audi</option>
   </select>
   <select name="cars" class="custom-select custom-select-lg mb-3">
      <option selected>Large Custom Select Menu</option>
      <option value="volvo">Volvo</option>
      <option value="fiat">Fiat</option>
      <option value="audi">Audi</option>
   </select>
</form>