Bootstrap 4 Navigation Bar

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</head>
<body>

<nav class="navbar navbar-expand-sm bg-light justify-content-center">
  <ul class="navbar-nav">
    <li class="nav-item">
      <a class="nav-link" href="#">Link 1</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Link 2</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Link 3</a>
    </li>
  </ul>
</nav>
<br>

<div class="container-fluid">
  <h3>Centered Navbar</h3>
  <p>Use the .justify-content-center class to center the navigation bar.</p>
  <p>In this example, the navbar will be centered on medium, large and extra large screens. On small screens it will be displayed vertically and left-aligned (because of the .navbar-expand-sm class).</p>
</div>

</body>
</html>

Bootstrap Example

Centered Navbar

Use the .justify-content-center class to center the navigation bar.

In this example, the navbar will be centered on medium, large and extra large screens. On small screens it will be displayed vertically and left-aligned (because of the .navbar-expand-sm class).