Bootstrap doesn’t include an icon library by default, but it has a handful of recommendations for you to choose from. While most icon sets include multiple file formats, we prefer SVG implementations for their improved accessibility and vector support.
This is an example of the CSS classes that Bootstrap provides for glyphicons. More of them are avalible <ahref='https://getbootstrap.com/docs/3.3/components/#glyphicons'target='_blank'rel='nofollow'>here</a>
Icon classes cannot be directly combined with other components. They should not be used along with other classes on the same element. Instead, add a nested `<span>` and apply the icon classes to the `<span>`.
**Only use icons on empty elements**
Icon classes should only be used on elements that contain no text content and have no child elements.
_Note: Bootstrap's Glyphicons icon is not avalable on bootstrap V4. However, it still works with V3.3.7 which is avaialble at the link provided below_.