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.


                <!-- Follow these instructions, please! -->
<div class="container py-5">
  <h1 class="h2">Bootstrap v5 Bug Report</h1>
  <p>Have a bug report to share with us? Use this template to reproduce an isolated test case so we can more easily identify the problem and hopefully find a fix.</p>
    <a class="btn btn-primary" href="" rel="noopener noreferrer" target="_blank">Read bug report guidelines</a>
  <p>Once you're set, replace the contents of this page and share the link with us in a <a href="" rel="noopener noreferrer" target="_blank">new issue</a>.</p>
  <p>Thanks! <span class="text-danger">♥</span></p>