Since Bootstrap 3 doesn't have a style for checkboxes I found a custom made that goes really well with Bootstrap style.
.checkbox label:after {_x000D_
content: '';_x000D_
display: table;_x000D_
clear: both;_x000D_
}_x000D_
_x000D_
.checkbox .cr {_x000D_
position: relative;_x000D_
display: inline-block;_x000D_
border: 1px solid #a9a9a9;_x000D_
border-radius: .25em;_x000D_
width: 1.3em;_x000D_
height: 1.3em;_x000D_
float: left;_x000D_
margin-right: .5em;_x000D_
}_x000D_
_x000D_
.checkbox .cr .cr-icon {_x000D_
position: absolute;_x000D_
font-size: .8em;_x000D_
line-height: 0;_x000D_
top: 50%;_x000D_
left: 15%;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"] {_x000D_
display: none;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]+.cr>.cr-icon {_x000D_
opacity: 0;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]:checked+.cr>.cr-icon {_x000D_
opacity: 1;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]:disabled+.cr {_x000D_
opacity: .5;_x000D_
}
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
_x000D_
<!-- Default checkbox -->_x000D_
<div class="checkbox">_x000D_
<label>_x000D_
<input type="checkbox" value="">_x000D_
<span class="cr"><i class="cr-icon glyphicon glyphicon-ok"></i></span>_x000D_
Option one_x000D_
</label>_x000D_
</div>_x000D_
_x000D_
<!-- Checked checkbox -->_x000D_
<div class="checkbox">_x000D_
<label>_x000D_
<input type="checkbox" value="" checked>_x000D_
<span class="cr"><i class="cr-icon glyphicon glyphicon-ok"></i></span>_x000D_
Option two is checked by default_x000D_
</label>_x000D_
</div>_x000D_
_x000D_
<!-- Disabled checkbox -->_x000D_
<div class="checkbox disabled">_x000D_
<label>_x000D_
<input type="checkbox" value="" disabled>_x000D_
<span class="cr"><i class="cr-icon glyphicon glyphicon-ok"></i></span>_x000D_
Option three is disabled_x000D_
</label>_x000D_
</div>
_x000D_
.checkbox label:after,_x000D_
.radio label:after {_x000D_
content: '';_x000D_
display: table;_x000D_
clear: both;_x000D_
}_x000D_
_x000D_
.checkbox .cr,_x000D_
.radio .cr {_x000D_
position: relative;_x000D_
display: inline-block;_x000D_
border: 1px solid #a9a9a9;_x000D_
border-radius: .25em;_x000D_
width: 1.3em;_x000D_
height: 1.3em;_x000D_
float: left;_x000D_
margin-right: .5em;_x000D_
}_x000D_
_x000D_
.radio .cr {_x000D_
border-radius: 50%;_x000D_
}_x000D_
_x000D_
.checkbox .cr .cr-icon,_x000D_
.radio .cr .cr-icon {_x000D_
position: absolute;_x000D_
font-size: .8em;_x000D_
line-height: 0;_x000D_
top: 50%;_x000D_
left: 13%;_x000D_
}_x000D_
_x000D_
.radio .cr .cr-icon {_x000D_
margin-left: 0.04em;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"],_x000D_
.radio label input[type="radio"] {_x000D_
display: none;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]+.cr>.cr-icon,_x000D_
.radio label input[type="radio"]+.cr>.cr-icon {_x000D_
opacity: 0;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]:checked+.cr>.cr-icon,_x000D_
.radio label input[type="radio"]:checked+.cr>.cr-icon {_x000D_
opacity: 1;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]:disabled+.cr,_x000D_
.radio label input[type="radio"]:disabled+.cr {_x000D_
opacity: .5;_x000D_
}
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.0.10/css/all.css" integrity="sha384-+d0P83n9kaQMCwj8F4RJB66tzIwOKmrdb46+porD/OvrJ+37WqIM7UoBtwHO6Nlg" crossorigin="anonymous">_x000D_
_x000D_
<!-- Default radio -->_x000D_
<div class="radio">_x000D_
<label>_x000D_
<input type="radio" name="o3" value="">_x000D_
<span class="cr"><i class="cr-icon fa fa-circle"></i></span>_x000D_
Option one_x000D_
</label>_x000D_
</div>_x000D_
_x000D_
<!-- Checked radio -->_x000D_
<div class="radio">_x000D_
<label>_x000D_
<input type="radio" name="o3" value="" checked>_x000D_
<span class="cr"><i class="cr-icon fa fa-circle"></i></span>_x000D_
Option two is checked by default_x000D_
</label>_x000D_
</div>_x000D_
_x000D_
<!-- Disabled radio -->_x000D_
<div class="radio disabled">_x000D_
<label>_x000D_
<input type="radio" name="o3" value="" disabled>_x000D_
<span class="cr"><i class="cr-icon fa fa-circle"></i></span>_x000D_
Option three is disabled_x000D_
</label>_x000D_
</div>
_x000D_
You can choose your own icon between the ones from Bootstrap or Font Awesome by changing [icon name]
with your icon.
<span class="cr"><i class="cr-icon [icon name]"></i>
For example:
glyphicon glyphicon-remove
for Bootstrap, orfa fa-bullseye
for Font Awesome.checkbox label:after,_x000D_
.radio label:after {_x000D_
content: '';_x000D_
display: table;_x000D_
clear: both;_x000D_
}_x000D_
_x000D_
.checkbox .cr,_x000D_
.radio .cr {_x000D_
position: relative;_x000D_
display: inline-block;_x000D_
border: 1px solid #a9a9a9;_x000D_
border-radius: .25em;_x000D_
width: 1.3em;_x000D_
height: 1.3em;_x000D_
float: left;_x000D_
margin-right: .5em;_x000D_
}_x000D_
_x000D_
.radio .cr {_x000D_
border-radius: 50%;_x000D_
}_x000D_
_x000D_
.checkbox .cr .cr-icon,_x000D_
.radio .cr .cr-icon {_x000D_
position: absolute;_x000D_
font-size: .8em;_x000D_
line-height: 0;_x000D_
top: 50%;_x000D_
left: 15%;_x000D_
}_x000D_
_x000D_
.radio .cr .cr-icon {_x000D_
margin-left: 0.04em;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"],_x000D_
.radio label input[type="radio"] {_x000D_
display: none;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]+.cr>.cr-icon,_x000D_
.radio label input[type="radio"]+.cr>.cr-icon {_x000D_
opacity: 0;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]:checked+.cr>.cr-icon,_x000D_
.radio label input[type="radio"]:checked+.cr>.cr-icon {_x000D_
opacity: 1;_x000D_
}_x000D_
_x000D_
.checkbox label input[type="checkbox"]:disabled+.cr,_x000D_
.radio label input[type="radio"]:disabled+.cr {_x000D_
opacity: .5;_x000D_
}
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.0.10/css/all.css" integrity="sha384-+d0P83n9kaQMCwj8F4RJB66tzIwOKmrdb46+porD/OvrJ+37WqIM7UoBtwHO6Nlg" crossorigin="anonymous">_x000D_
_x000D_
<div class="checkbox">_x000D_
<label>_x000D_
<input type="checkbox" value="" checked>_x000D_
<span class="cr"><i class="cr-icon glyphicon glyphicon-remove"></i></span>_x000D_
Bootstrap - Custom icon checkbox_x000D_
</label>_x000D_
</div>_x000D_
_x000D_
<div class="radio">_x000D_
<label>_x000D_
<input type="radio" name="o3" value="" checked>_x000D_
<span class="cr"><i class="cr-icon fa fa-bullseye"></i></span>_x000D_
Font Awesome - Custom icon radio checked by default_x000D_
</label>_x000D_
</div>_x000D_
<div class="radio">_x000D_
<label>_x000D_
<input type="radio" name="o3" value="">_x000D_
<span class="cr"><i class="cr-icon fa fa-bullseye"></i></span>_x000D_
Font Awesome - Custom icon radio_x000D_
</label>_x000D_
</div>
_x000D_