You can use override the default Bootstrap CSS like this…
.navbar-header {
float: none;
}
.navbar-toggle {
display: block;
}
.navbar-collapse {
border-top: 1px solid transparent;
box-shadow: inset 0 1px 0 rgba(255,255,255,0.1);
}
.navbar-collapse.collapse {
display: none!important;
}
.navbar-nav {
float: none!important;
margin: 7.5px -15px;
}
.navbar-nav>li {
float: none;
}
.navbar-nav>li>a {
padding-top: 10px;
padding-bottom: 10px;
}
Demo: http://www.bootply.com/114896
This will ensure that the collapsed navbar is always used by overriding the Bootstrap @media queries.
Update: For Bootstrap 4, you just need to remove the navbar-toggleable
class:
http://www.codeply.com/go/LN6szcJO53