Buttons are used to carry out actions. Use them when you should enable or initiate an immediate action within your application e.g. “OK”, ”Save”, ”Continue” or ”Submit.” Read more about buttons in the UX Guidelines.
Use the button classes on an <a>, <button>, or <input> element. Also you can use any of the available button classes to quickly create a styled button: .btn-default or .btn-primary or even to large version of it: .btn-lg
Use the primary (green) button to:
Highlight the primary action in the screen, which shall be the main and/or finalising action
Emphasise either normal buttons, menu buttons or split buttons
Design
Use any of the available button classes to quickly create a styled button. For the default style you can simply add .btn and for the primary style add .btn-primary
Fancy larger buttons? Add .btn-lg for a larger size.
<buttontype="button"class="btn btn-lg">Default large button</button>
<buttontype="button"class="btn btn-lg left">Default left large button</button>
<buttontype="button"class="btn btn-lg right">Default right large button</button>
<buttontype="button"class="btn btn-primary btn-lg left">Primary left large button</button>
<buttontype="button"class="btn btn-primary btn-lg right">Primary right large button</button>
States
Below you can find each type of button (default and primary) and how it should look for each state (normal, hover, pressed, active/selected and disabled). For active/selected state you need to add .active class on the element and include the aria-selected="true" attribute to indicate the state of the element to assistive technologies.
Normal
:hover
:active (Pressed)
.active (Selected)
:focus
:disabled
Disabled state
Make buttons look unclickable by adding a custom colour. Add .disabled class on your button or add the disabled attribute to <button> or <input> buttons.
<a> tag don't support the disabled attribute, so you must add the .disabled class to make it visually appear disabled
For disabled buttons, that include .disabled class and <a> tag, they should include the aria-disabled="true" attribute to indicate the state of the element to assistive technologies.
<divclass="col-4"><buttontype="button"class="btn btn-lg btn-block">Block level default large button</button></div>
<divclass="col-4"><buttontype="button"class="btn btn-lg btn-primary btn-block">Block level primary large button</button></div>
Link buttons (with and without icons) and icon buttons
You can also use .btn-link and .btn-icon. Both will have the height of a default button but won't have the button styling.
Checkout the examples below.