Buttons
buttons.less
Use the button classes on an <a>
, <button>
, or <input>
element.
<a class="btn btn-default" href="#" role="button">Link</a>
<button class="btn btn-default" type="submit">Button</button>
<input class="btn btn-default" type="button" value="Input">
<input class="btn btn-default" type="submit" value="Submit">
Context-specific usage
While button classes can be used on
<a>
and<button>
elements, only<button>
elements are supported within our nav and navbar components.
Links acting as buttons
If the
<a>
elements are used to act as buttons – triggering in-page functionality, rather than navigating to another document or section within the current page – they should also be given an appropriaterole="button"
.
Cross-browser rendering
As a best practice, we highly recommend using the
<button>
element whenever possible to ensure matching cross-browser rendering.Among other things, there's a bug in Firefox <30 that prevents us from setting the
line-height
of<input>
- based buttons, causing them to not exactly match the height of other buttons on Firefox.
Options
Use any of the available button classes to quickly create a styled button.
Conveying meaning to assistive technologies
Using color to add meaning to a button only provides a visual indication, which will not be conveyed to users of assistive technologies – such as screen readers. Ensure that information denoted by the color is either obvious from the content itself (the visible text of the button), or is included through alternative means, such as additional text hidden with the
.sr-only
class.
Sizes
Fancy larger or smaller buttons? Add .btn-lg
, .btn-sm
, or .btn-xs
for additional sizes.
Create block level buttons—those that span the full width of a parent— by adding .btn-block
.
Active state
Buttons will appear pressed (with a darker background, darker border, and inset shadow) when active. For <button>
elements, this is done via :active
. For <a>
elements, it's done with .active
. However, you may use .active
on <button>
s (and include the aria-pressed="true"
attribute) should you need to replicate the active state programmatically.
Button element
No need to add :active
as it's a pseudo-class, but if you need to force the same appearance, go ahead and add .active
.
Anchor element
Add the .active
class to <a>
buttons.
Disabled state
Make buttons look unclickable by fading them back with opacity
.
Button element
Add the disabled
attribute to <button>
buttons.
Cross-browser compatibility
If you add the
disabled
attribute to a<button>
, Internet Explorer 9 and below will render text gray with a nasty text-shadow that we cannot fix.
Anchor element
Add the .disabled
class to <a>
buttons.
We use .disabled as a utility class here, similar to the common .active class, so no prefix is required.
Link functionality caveat
This class uses
pointer-events: none
to try to disable the link functionality of<a>
s, but that CSS property is not yet standardized and isn't fully supported in Opera 18 and below, or in Internet Explorer 11. In addition, even in browsers that do supportpointer-events: none
, keyboard navigation remains unaffected, meaning that sighted keyboard users and users of assistive technologies will still be able to activate these links. So to be safe, use custom JavaScript to disable such links.