HTML редактор

<!doctype html>
<html lang="ru">

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <base href="https://itchief.ru">
  
  <link href="/examples/libs/bootstrap-3/css/bootstrap.min.css" rel="stylesheet">
  <title>Bootstrap 3 - Прижать футер к низу экрана</title>
  <style>
    html,
    body {
      height: 100%;
    }

.wrapper {
      display: flex;
      flex-direction: column;
      min-height: 100%;
    }

.wrapper>.content {
      flex: 1 0 auto;
    }

.wrapper>.footer {
      flex: 0 0 auto;
    }

/* для примера */
    .wrapper>.footer>.container-fluid {
      min-height: 100px;
      background-color: #757575;
    }
  </style>
</head>

<body>

<script src="/examples/libs/jquery/jquery-3.4.1.min.js"></script>
  
  <script src="/examples/libs/bootstrap-3/js/bootstrap.min.js"></script>

</body>

</html>