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Advanced Theme Code
Theme Code

Editing code is an exclusive feature available to seller on our premium plans. Need to upgrade? Explore our plans. 

The Code section in your shop designer is for sellers who are comfortable editing HTML and want deeper control over their shop’s design. This section allows for advanced design customizations that aren’t possible through the built-in design tools or by switching themes.

This is where you can:

  • Fully customize your HTML
  • Adjust your shop’s layout and navigation behavior
  • Create a completely unique storefront look and feel

Keep in mind that our built-in templates include many features, so be sure to explore them before considering custom code.

Important: Changes made in the Advanced template code section will be deleted if you switch or update your theme. You can always restore your previous version if needed using the instructions here.

Use the Integration Code Section for Updates

To avoid losing your changes during a theme update, we strongly recommend placing any code updates or persistent customizations in the Integration Code section instead of the Advanced template code section. Code added here stays in place even if you switch themes.

Use the Integration Code for:

  • Customizations you want to survive theme changes
  • Small visual tweaks or layout updates
  • Third-party scripts and tools (like Mailchimp, Pinterest, or Facebook Pixel)
  • External JavaScript, fonts, or stylesheet links

This approach ensures your changes won’t interfere with future template improvements and keeps your setup more maintainable.

Editing Tips

  • Add custom CSS in the Custom styling section to make it easy to manage or remove later.
  • Big Cartel themes use Liquid, a flexible templating language. Visit our Developer page for more advanced resources.
  • All files must be hosted externally—we don’t support file uploads (e.g., for custom scripts, fonts, or stylesheets).

Limitations

  • The checkout page is not editable.
  • Advanced template code changes do not carry over when you change themes. You can download your theme code to save a copy of your custom code to add back to the Advanced Theme Code section if you do update or switch themes.
  • If you're unsure about custom code, it’s a good idea to work with a designer.

If you need to add a script or tag from a third-party service, like Omnisend, Mailchimp, or Pinterest, paste those in the Integration Code section instead. Scripts added to the Integration Code will remain saved in your template unless you manually remove them or downgrade to our free Gold plan.

Additional Information about Advanced Customizations

We recommend that only people comfortable editing and maintaining custom code work in the Advanced Theme Code section. If you aren’t familiar with HTML/CSS and you need to customize your theme code, we recommend hiring a designer to assist you.
  • While most pages in your shop are accessible for advanced customizations, the checkout page is not editable at this time.
  • When editing your CSS, we recommend you place any custom code at the bottom of the CSS page instead of editing the code directly. This will allow you to easily adjust or remove any custom elements without having to reset your CSS to the default code.
  • Big Cartel themes use Liquid markup as the theme’s language. Check out our Developer page for more information about advanced tools available for developers.
  • You can include custom Javascript, stylesheets, or font files in the Integration Code and Advanced Theme Code sections. However, all files must be hosted externally—we don’t offer file hosting.
Have a specific coding question? Try posting on Stack Overflow or search their resources using a Big Cartel tag to find coding advice.

How to Edit Your Theme Code

  1. Log in at app.bigcartel.com
  2. Click Shop settings > Shop designers
  3. Select the Code tab
  4. Under the Integration Code section, click Head to place your code before the </head> tag, or click Body to place your code before the </body> tag
  5. If you're editing the Advanced Theme Code section, proceed with caution. In the Code tab, scroll to the Advanced template code area, select the section you want to edit, and make your changes
  6. When you’re finished, click Done
  7. To apply your changes, click Publish. To undo, click Discard. If you're not ready to publish, click Exit—your changes will be auto-saved but not published
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