Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

JavaScript

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                h1 Single-Image Retina Solution
p Double dimensions, crank the compression, scale to 50% in browser.
div
  img(src="https://dbox.us/_img/mbpro1x.jpg")
  h4 Original Non-Retina - 600 x 400 
  ul
    li Jpeg compressed at 80%
    li 
      b 37,418 bytes 
  
div.retina
  img(src="https://dbox.us/_img/mbpro%402x.jpg")
  h4 Retina - 1200 x 800
  ul
    li Jpeg compressed at 30%
    li Looks great on retina because tiny pixels don't pick up on extra compression
    li Looks great on standard because resampling hides compression
    li Actually smaller filesize!
    li 
      b.awesome 36,825 bytes
  
              
            
!

CSS

              
                div
  max-width: 600px
  width: 48%
  float: left
  margin-right: 1px
  
img
  width: 100%
  height: auto
  
.awesome
  color: green
  
              
            
!

JS

              
                
              
            
!
999px

Console