Bootstrap CSS space between buttons in navbar

you may try margin-left

here is the code

.btn{
margin-left:10px;
}

here is the example:: FIDDLE

Copy & paste this to your style.css and assign it as class attribute:

.btn-margin-left {
    margin-left: 2px;
}
.btn-margin-right {
    margin-right: 2px;
}

Usage

<a href="URL" class="btn btn-default btn-sm btn-margin-left">Link</a>

<button type="button" class="btn btn-default btn-sm btn-margin-left">Button</button>