bootstrap 4 search bar
snippet in html

bootstrap 4 search bar

user7283

<form class="form-inline">
  <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
  <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
</form>

html search input

user8051

<input type="search">

search bar html

user1233

<input type="text" name="search">