Yes — you can absolutely add custom code to your Atlas theme, just like you would with any Shopify theme.
The Atlas theme is fully compatible with:
Custom HTML, CSS, and JavaScript
Custom Liquid blocks
Third-party scripts like tracking pixels, widgets, or integrations
How to add custom code
1. Using the Shopify theme editor (no coding required):
Go to Online Store > Themes > Customize
Inside of any Atlas theme section you can scroll down to the bottom and open the "Custom CSS" tab
Paste in your embed code, widget script, or custom code
2. Editing the theme files directly:
Go to Online Store > Themes
Click Actions > Edit code
From here, you can modify:
theme.liquidproduct.liquid,collection.liquid, etc.Any custom CSS or JS files
Best Practices
Always duplicate your theme before making edits
Be cautious when editing core layout files — one missing bracket can break the layout
For advanced use cases (like animations or checkout integrations), consider working with a Shopify developer
tip:
If you’re not comfortable editing theme code, we recommend using the Custom Liquid block to safely insert scripts or embeds without risk.
Let me know if you’d like this cross-linked under the customization section as well.