Answers for "bootstrap 4 input box"

large input box bootstrap 4

.form-control-sm
.form-control-lg

input with bootstrap

<form>
  <div class="form-group">
    <label for="exampleInputEmail1">Email address</label>
    <input type="email" class="form-control">
    <small id="emailHelp" class="form-text text-muted">Hello, World</small>
  </div>
 </form>

bootstrap input tagsinput

<select multiple data-role="tagsinput">
  <option value="Amsterdam">Amsterdam</option>
  <option value="Washington">Washington</option>
  <option value="Sydney">Sydney</option>
  <option value="Beijing">Beijing</option>
  <option value="Cairo">Cairo</option>
</select>