Pen Settings



CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource


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


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.


Auto Save

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.


                <div class="container">
  <p>But almost before the invention of the hot-air balloon had been completed, and before Pilâtre de Rozier had made his ascent, a rival craft had appeared upon the scene, to which we must more specially refer in the next chapter.</p>
      <img src="" alt="3 people in Victorian clothes in a balloon">
      <figcaption>The Authoress, her Father and Mr. Spencer making an ascent</figcaption>

  <h2>The Coming of The Gas Balloon</h2>
<p>During the time of which we are speaking there was living in London a famous chemist named Henry Cavendish. He was the son of a nobleman, and a very rich man; but he shut himself up entirely from the world, and devoted his whole time and energies to the study of science. So afraid was he of being interrupted in his work that he lived the life of a hermit, commanding his servants to keep out of his sight on pain of dismissal, and ordering his dinner daily by means of a note placed on the hall table. In the year 1760—twenty-two years before the Montgolfier brothers began their experiments—this eccentric man had discovered what was then known as “inflammable air,” but what we now call hydrogen gas.</p>


                body {
  padding: 2em;
  font: 1em/1.5 'Open Sans', sans-serif;
  color: #333;

figure {
  margin: 0;
  break-inside: avoid;

figcaption {
  font: .9em 'Berkshire Swash', cursive;
  text-align: center;

img {
  max-width: 100%;

h2 {
  font: 1.4em 'Berkshire Swash', cursive;

.container {
  max-width: 800px;
  margin: 0 auto;
  column-width: 14em;