Default buttons
Button styles can be applied to anything with the .btn class applied. However, typically you'll want to apply these to only <a> and <button> elements for the best rendering.
    
        
            | Button | 
            class="" | 
            Description | 
        
    
    
        
             | 
            btn | 
            Standard gray button with gradient | 
        
        
             | 
            btn btn-primary | 
            Provides extra visual weight and identifies the primary action in a set of buttons | 
        
        
             | 
            btn btn-info | 
            Used as an alternative to the default styles | 
        
        
             | 
            btn btn-success | 
            Indicates a successful or positive action | 
        
        
             | 
            btn btn-warning | 
            Indicates caution should be taken with this action | 
        
        
             | 
            btn btn-danger | 
            Indicates a dangerous or potentially negative action | 
        
        
             | 
            btn btn-inverse | 
            Alternate dark gray button, not tied to a semantic action or use | 
        
        
             | 
            btn btn-link | 
            Deemphasize a button by making it look like a link while maintaining button behavior | 
        
    
Cross browser compatibility
IE9 doesn't crop background gradients on rounded corners, so we remove it. Related, IE9 jankifies disabled button elements, rendering text gray with a nasty text-shadow that we cannot fix.
Button sizes
Fancy larger or smaller buttons? Add .btn-large, .btn-small, or .btn-mini for additional sizes.
 
<p>
  <button class="btn btn-large btn-primary" type="button">Large button</button>
  <button class="btn btn-large" type="button">Large button</button>
</p>
<p>
  <button class="btn btn-primary" type="button">Default button</button>
  <button class="btn" type="button">Default button</button>
</p>
<p>
  <button class="btn btn-small btn-primary" type="button">Small button</button>
  <button class="btn btn-small" type="button">Small button</button>
</p>
<p>
  <button class="btn btn-mini btn-primary" type="button">Mini button</button>
  <button class="btn btn-mini" type="button">Mini button</button>
</p>
Create block level buttons—those that span the full width of a parent— by adding .btn-block.
 
<button class="btn btn-large btn-block btn-primary" type="button">Block level button</button>
<button class="btn btn-large btn-block" type="button">Block level button</button>
Disabled state
Make buttons look unclickable by fading them back 50%.
Anchor element
Add the .disabled class to <a> buttons.
Primary link
Link
<a href="#" class="btn btn-large btn-primary disabled">Primary link</a>
<a href="#" class="btn btn-large disabled">Link</a>
Heads up!
We use .disabled as a utility class here, similar to the common .active class, so no prefix is required. Also, this class is only for aesthetic; you must use custom JavaScript to disable links here.
Button element
Add the disabled attribute to <button> buttons.
<button type="button" class="btn btn-large btn-primary disabled" disabled="disabled">Primary button</button>
<button type="button" class="btn btn-large" disabled>Button</button>
One class, multiple tags
Use the .btn class on an <a>, <button>, or <input> element.
<a class="btn" href="">Link</a>
<button class="btn" type="submit">Button</button>
<input class="btn" type="button" value="Input">
<input class="btn" type="submit" value="Submit">
As a best practice, try to match the element for your context to ensure matching cross-browser rendering. If you have an input, use an <input type="submit"> for your button.