Bootstrap 3 Flush footer to bottom. not fixed

There is a simplified solution from bootstrap here (where you don't need to create a new class): http://getbootstrap.com/examples/sticky-footer-navbar/

When you open that page, right click on a browser and "View Source" and open the sticky-footer-navbar.css file (http://getbootstrap.com/examples/sticky-footer-navbar/sticky-footer-navbar.css)

you can see that you only need this CSS

/* Sticky footer styles
-------------------------------------------------- */
html {
  position: relative;
  min-height: 100%;
}
body {
  /* Margin bottom by footer height */
  margin-bottom: 60px;
}
.footer {
  position: absolute;
  bottom: 0;
  width: 100%;
  /* Set the fixed height of the footer here */
  height: 60px;
  background-color: #f5f5f5;
}

for this HTML

<html>
    ...
    <body>
        <!-- Begin page content -->
        <div class="container">
        </div>
        ...

        <footer class="footer">
        </footer>
    </body>
</html>

UPDATE: This does not directly answer the question in its entirety, but others may find this useful.

This is the HTML for your responsive footer

<footer class="footer navbar-fixed-bottom">
     <div class="container">
     </div>
</footer>

For the CSS

footer{
    width:100%;
    min-height:100px;    
    background-color: #222; /* This color gets inverted color or you can add navbar inverse class in html */
}

NOTE: At the time of the posting for this question the above lines of code does not push the footer below the page content; but it will keep your footer from crawling midway up the page when there is little content on the page. For an example that does push the footer below the page content take a look here http://getbootstrap.com/examples/sticky-footer/


use flexbox as you can use it at your disposal. The solution offered by bootstrap 4 still hunting overlap content in responsive layout, e.g: it will break in mobile view, i come across the most neat trick is to use flexbox solution demo shown at here:(https://philipwalton.github.io/solved-by-flexbox/demos/sticky-footer/) this way we do not have to deal with fixed height issue which is an obsolete solution by now...this solution works for bootstrap 3 and 4 whichever you using.

<body class="Site">
  <header>…</header>
  <main class="Site-content">…</main>
  <footer>…</footer>
</body>

.Site {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

.Site-content {
  flex: 1;
}

See the example below. This will position your Footer to stick to bottom if the page has less content and behave like a normal footer if the page has more content.

CSS

* {
    margin: 0;
}
html, body {
    height: 100%;
}
.wrapper {
    min-height: 100%;
    height: 100%;
    margin: 0 auto -155px; /* the bottom margin is the negative value of the footer's height */
}
.footer, .push {
    height: 155px; /* .push must be the same height as .footer */
}

HTML

<div class="wrapper">
  <p>Your website content here.</p>
  <div class="push"></div>
</div>
<div class="footer">
  <p>Copyright (c) 2008</p>
</div>

UPDATE: New version of Bootstrap demonstrates how to add sticky footer without adding a wrapper. Please see Jboy Flaga's Answer for more details.